The Quants: How a New Breed of Math Whizzes Conquered Wall Street and Nearly Destroyed It

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The Quants: How a New Breed of Math Whizzes Conquered Wall Street and Nearly Destroyed It Page 6

by Scott Patterson

“What’s it called?” Bamberger asked.

  “Princeton/Newport Partners,” Taylor told him. “Run by a guy named Ed Thorp.”

  Thorp, Taylor explained, was always interested in new strategies and was interested in looking at stat arb. Taylor introduced Bamberger to Jay Regan, and the two hit it off. Thorp and Regan agreed to back a fund called BOSS Partners, an acronym for Bamberger and Oakley Sutton Securities (Oakley and Sutton are Thorp and Regan’s middle names, respectively). Bamberger set up shop in a 120-square-foot twelfth-floor office on West 57th Street in New York. With $5 million in capital, he hit the ground running, cranking out an annualized return of about 30 percent his first year in operation. By 1988, BOSS was running about $100 million in assets and generating consistent double-digit returns.

  BOSS, like APT, hit a dry spell in early 1988. Toward the end of the year, Bamberger decided he’d had enough of Wall Street. He wound down BOSS and moved upstate to teach finance and law at the State University of New York at Buffalo. He never again traded stocks on a large scale.

  But his strategy lived on, and not just at Princeton/Newport. Traders who’d worked for Bamberger and Tartaglia fanned out across Wall Street, bringing stat arb to hedge funds and investment banks such as Goldman Sachs. As D. E. Shaw raked in profits, other funds started trying to copy its superfast trading style. Robert Frey, who’d worked as an APT researcher, took stat arb to Jim Simons’s fund, Renaissance Technologies, in the early 1990s. Peter Muller, the singing quant who triumphed at Wall Street Poker Night in 2006, appeared on the scene at Morgan a few years after Tartaglia was ousted and started up his own stat-arb money machine, one that proved far more robust. Ken Griffin, who kept a keen eye on everything Thorp was doing, adopted the strategy at Citadel. Stat arb soon became one of the most popular and consistent ways to make money on Wall Street—too popular, in fact, as its practitioners would discover in August 2007.

  Ed Thorp’s influence was spreading across the financial universe in other ways as well. At MIT, a team of blackjack card counters sprung up, the group that would eventually inspire the bestselling book Bringing Down the House. An early member of the group was a young math hotshot named Blair Hull, who’d read Beat the Dealer in the early 1970s. By the end of the decade, he’d parlayed $25,000 in winnings to jump-start a trading career in the Chicago options trading pits, having also read Beat the Market. In 1985, he founded Hull Trading, which specialized in using quantitative models and computers to price options on a rapid-fire basis. Hull eventually became one of the most advanced trading operations in the world, a quant mecca that transformed the options world. In 1999, Goldman Sachs shelled out $531 million for Hull, which it developed into one of Wall Street’s premier high-frequency trading outfits.

  For Thorp and Regan, meanwhile, everything had been running smoothly. The fund had posted solid gains in 1986 and was surging ahead in the first half of 1987, helped by BOSS’s gains. Then stocks started to wobble. By early October, cracks were forming in the market that would turn into a full-blown earthquake. At the heart of the disaster: the quants and the Black-Scholes option-pricing formula.

  Sometime around midnight, October 19, 1987, Leo Melamed reached out a sweaty-palmed hand, picked up the phone in his nineteenth-floor office at the Chicago Mercantile Exchange, and dialed Alan Greenspan. The newly appointed chairman of the Federal Reserve, Greenspan was staying at the upscale Adolphus Hotel in Dallas to address the American Bankers Association’s annual convention the next day. It was to be his first major speech as chairman of the central bank.

  The speech would never happen. The Dow industrials had crashed, losing 23 percent in a single day. Other exchanges, including the Merc, were in chaos. Many players in the market were bankrupt and couldn’t settle their bills. Greenspan had been fielding calls from executives at nearly every major bank and exchange in the country. His single goal: make sure the markets were up and running Tuesday morning.

  Greenspan wanted to know if the Merc would make it. Melamed, the exchange’s president, wasn’t sure. The Merc had become a trading hub for a new financial product, futures contracts linked to the S&P 500. At the end of a typical trading day, traders who’d lost money on any contracts would transfer cash to the Merc’s clearinghouse, which would deposit the money into the winners’ accounts. Typically $120 million would change hands every day. But that Monday, buyers of S&P futures owed sellers an amount in the range of $2 billion to $3 billion. Some couldn’t pay.

  If the Merc couldn’t open its doors for business, the panic would spread. The whole system could come crashing down. That night, Melamed made frantic phone calls to institutions around the country trying to settle accounts. By morning, $2.1 billion in transfers had been completed, but a single client still owed $400 million to Continental Illinois, the Merc’s financing agent.

  Melamed still wasn’t sure if the Merc could open without that $400 million. Around 7:00 A.M. he decided to call Wilma Smelcer, Continental’s financial officer in charge of the bank’s account with the Merc. If Smelcer couldn’t help him, his next call would be to Greenspan … with very bad news.

  Smelcer didn’t think she could look past $400 million in missing funds. It was a deal killer. “Wilma, I am certain your customer is good for it,” Melamed pleaded. “You’re not going to let a stinking couple of hundred million dollars cause the Merc to go down the tubes, are you?”

  “Leo, my hands are tied.”

  “Please listen, Wilma. You have to take it upon yourself to guarantee the balance, because if you don’t, I’ve got to call Alan Greenspan, and we’re going to cause the next depression.”

  After a few moments of tense silence, Smelcer said, “Hold it a minute, Leo. Tom Theobald just walked in.” Theobald was chairman of Continental.

  After a few minutes, Smelcer was back. “Leo, we’re okay. Tom said go ahead. You’ve got your money.”

  It was 7:17 A.M., three minutes before the opening of the Merc’s currency markets. The world had little idea how close the financial system had come to a catastrophic seizure.

  The critical factor behind the crash of Black Monday on October 19, 1987, can be traced to a restless finance professor’s sleepless night more than a decade earlier. The result of that night would be a feat of financial engineering called portfolio insurance. Based on the Black-Scholes formula, portfolio insurance would scramble the inner workings of the stock market and set the stage for the single largest one-day market collapse in history.

  On the evening of September 11, 1976, Hayne Leland, a thirty-five-year-old professor at the University of California at Berkeley, was having trouble sleeping. He’d recently returned from a trip to France. A weak dollar had made the trip excessively pricey. Stagflation, a crippling mix of high inflation and slow growth, was rampant. The economy and the stock market were in the tank. California governor Ronald Reagan was threatening cutbacks in the salaries of academics such as Leland, who worried that the prosperous American lifestyle of his parents’ generation was in danger.

  As he pondered this bleak reality, Leland recalled a conversation he’d had with his brother, John, who worked at an investment management company in San Francisco. Stocks had cratered in 1973, and pension funds had pulled out en masse, missing out on a bounce that followed. “If only insurance were available,” John had said, “those funds could be attracted back to the market.”

  Leland was familiar with the Black-Scholes formula and knew that options behaved in ways like insurance. A put option, which pays off if a stock drops, is akin to an insurance policy on a stock. He thought of it step by step. Say I own IBM at $50 and am worried about it losing value. I can buy a put for $3 that pays off if IBM falls to $45 (allowing me to unload it for $50), essentially insuring myself against the decline for a premium of $3.

  Leland realized his brother had been describing a put option on an entire portfolio of stocks. He sat down at his desk and started to scribble out the implications of his revelation. If the risk of an entire portfolio of stocks de
clining could be quantified, and if insurance could cover it, then risk would be controlled and managed, if not effectively eliminated. Thus portfolio insurance was born. No more sleepless nights for jittery professors.

  Over the next few years, Leland and a team of financial engineers, including Mark Rubinstein and John O’Brien, created a product that would provide insurance for large portfolios of stocks, with the Black-Scholes formula as a guidepost. In 1981, they formed Leland O’Brien Rubinstein Associates Inc., later known simply as LOR. By 1984, business was booming. The product grew even more popular after the Chicago Mercantile Exchange started trading futures contracts tied to the S&P 500 index in April 1982. The financial wizards at LOR could replicate their portfolio insurance product by shorting S&P index futures. If stocks fell, they would short more futures contracts. Easy, simple, and sweet. And enormously profitable.

  By the autumn of 1987, the company’s portfolio insurance protected $50 billion in assets held by institutional investors, mostly pension funds. Add in LOR copycats and the total amount of equity backed by portfolio insurance was roughly $100 billion.

  The Dow industrials had soared through the first half of 1987, gaining more than 40 percent by late August. The so-called Reagan Revolution had restored confidence in America. Inflation was in retreat. Japanese investors were flooding the United States with yen. New Agers around the country discovered the healing power of crystals. A new, young Fed chairman was in town. The New York Mets were the Cinderella world champions of baseball, having won the 1986 World Series in seven games, led by a young power hitter named Darryl Strawberry and a dazzling pitcher named Dwight Gooden. What could go wrong?

  Plenty. By mid-October, the market had been knocked for a loop, tumbling 15 percent in just a few months. The block trading desk at Shearson Lehman Brothers installed a metal sign with an arrow that read: “To the Lifeboats.”

  The mood was grim. Traders talked of chain reaction declines triggered by mysterious computer-assisted trading strategies in stocks and futures markets. As trading wound down on Friday, October 16, a trader in stock index options on the floor of the American Stock Exchange shrieked, “It’s the end of the world!”

  Early on Monday, October 19, investors in New York were bracing for an onslaught well before trading began. Over in the Windy City, it was eerily quiet in the stock index futures pit at the Chicago Mercantile Exchange as traders waited for the action to begin. All eyes were on Chicago’s “shadow markets,” whose futures anticipate the behavior of actual prices. Seconds after the open at the Merc—fifteen minutes ahead of trading in New York—S&P 500 index futures dropped 14 points, indicating a 70-point slump in the Dow industrials.

  Over the next fifteen minutes before trading began on the NYSE, massive pressure built up on index futures, almost entirely from portfolio insurance firms. The big drop by index futures triggered a signal for another new breed of trader: index arbitrageurs, investors taking advantage of small discrepancies between indexes and underlying stocks. When trading opened in New York, a brick wall of short selling slammed the market. As stocks tumbled, pressure increased on portfolio insurers to sell futures, racing to keep up with the widely gapping market in a devastating feedback loop. The arbs scrambled to put on their trades but were overwhelmed: futures and stocks were falling in unison. Chaos ruled.

  Fischer Black watched the disaster with fascination from his perch at Goldman Sachs in New York, where he’d taken a job managing quantitative trading strategies. Robert Jones, a Goldman trader, dashed into Black’s office to report on the carnage. “I put in an order to sell at market and it never filled,” he said, describing a frightening scenario in which prices are falling so fast there seems to be no set point where a trade can be executed. “Wow, really?” Black said, clapping his hands with glee. “This is history in the making!”

  In the final seventy-five minutes of trading on October 19, the decline hit full throttle as portfolio insurance sellers dumped futures and sell orders flowed in from brokerage accounts around the country. The Dow snapped, sliding 300 points, triple the amount it had ever dropped in a single day in history and roughly the equivalent of a 1,500-point drop in today’s market. The blue chip average finished the day at 1738.74, having dropped 508 points.

  In the new globally interlaced electronic marketplace, the devastation wound around the globe like a poisonous serpent Monday night, hitting markets in Tokyo, Hong Kong, Paris, Zurich, and London, then making its way back to New York. Early Tuesday, during a brief, gut-wrenching moment, the market would lurch even deeper into turmoil than Black Monday. The blue-chip average opened down more than 30 percent. Stocks, options, and futures trading froze. It was an all-out meltdown.

  Over in Newport Beach, Thorp’s team was scrambling. Thorp had watched in dismay Monday as the market fell apart. By the time he got back from a hastily snatched lunch, it had lost 23 percent. Trading was closed, and Thorp had a severe case of heartburn. But he quickly figured out that portfolio insurance was behind the market meltdown.

  As trading opened Tuesday, a huge gap between S&P futures and the corresponding cash market opened up. Normally, that meant a great trading opportunity for arbs, including Thorp, always attracted to quantitative strategies. The massive gap between futures contracts, created by the heavy selling by portfolio insurers, and their underlying stocks was a sign to buy futures and short stocks.

  By Tuesday, most of the arbs were terrified, having been crushed on Black Monday by the plummeting market. But Thorp was determined. His plan was to short the stocks in the index and buy the futures, gobbling up the big spread between the two.

  The trouble was getting the orders through in the fast-moving market. As soon as a buy or sell order was placed, it was left behind as the market continued to tumble. In the heat of the crisis, Thorp got Princeton/Newport’s head trader on the phone: “Buy $5 million worth of index futures at the market and short $10 million worth of stocks.”

  His best guess was that only half of the stock orders would be filled anyway because, due to technical reasons, it was hard to short stocks in the free-falling market.

  At first his trader balked. “Can’t, the market’s frozen.”

  Thorp threw the hammer down. “If you don’t fill these orders I’m going to do them in my own personal account. I’m going to hang you out to dry,” Thorp shouted, clearly implying that the trader’s firm wouldn’t share any of the profits.

  The trader reluctantly agreed to comply but was only able to make about 60 percent of the short sales Thorp had ordered up due to the volatility. Soon after, he did the trade again, pocketing more than $1 million in profits.

  Thorp’s calm leap into the chaos wasn’t the norm. Most market players were in a this-is-the-big-one hand-wringing frenzy.

  Then it stopped. Sometime Tuesday afternoon, the market landed on its feet. It started to climb as the Federal Reserve pumped massive sums of money into the system. The Dow finished the day up 102 points. The next day, it soared 186.84 points, its biggest one-day point advance in history at the time.

  But the damage had been done. The mood around the country turned decidedly anti–Wall Street as the junk bond scandals hit the front pages of newspapers. An October 1987 Newsweek cover queried, “Is the Party Over? A Jolt for Wall Street’s Whiz Kids.” In December 1987, audiences in movie theaters listened to Gordon Gekko, the slimy takeover artist played by Michael Douglas, proclaim the mantra for the decade in Oliver Stone’s Wall Street: “Greed is good.” A series of popular books reflecting the anti–Wall Street sentiment hit the presses: Bonfire of the Vanities by Tom Wolfe, Barbarians at the Gate by Wall Street Journal reporters Bryan Burrough and John Helyar, The Predators’ Ball by Connie Bruck, Liar’s Poker by Michael Lewis.

  The quants were licking their wounds. Their wondrous invention, portfolio insurance, was roundly blamed for the meltdown. Fama’s efficient-market theory was instantly called into question. How could the market be “right” one day, then suffer a 23 percent co
llapse on virtually no new information the next day, then be fine the day after?

  The now-you-see-it-now-you-don’t math wizards had a unique retort: Black Monday never happened. Jens Carsten Jackwerth, a postdoctoral visiting scholar at the University of California at Berkeley, and Mark Rubinstein, coinventor of portfolio insurance, offered incontrovertible proof that October 19, 1987, was statistically impossible. According to their probability formula, published in 1995, the likelihood of the crash was a “27-standard-deviation event,” with a probability of 10 to the 160th power: “Even if one were to have lived through the entire 20 billion year life of the universe and experienced this 20 billion times (20 billion big bangs), that such a decline could have happened even once in this period is a virtual impossibility.”

  Still, the very real crash on Black Monday left very real scars on the psyches of the traders who witnessed it, from the trading pits of Chicago to the exchange floors of lower Manhattan. Meltdowns of such magnitude and ferocity were not supposed to happen in the world’s most advanced and sophisticated financial marketplace.

  They especially weren’t supposed to happen in a randomized, Brownian motion world in which the market obeyed neat statistical rules. A 27-standard-deviation event was tantamount to flipping a coin a hundred times and getting ninety-nine straight heads.

  Was there a worm in the apple, a fatal flaw in the quants’ theory? This haunting fear, brought on by Black Monday, would hover over them like a bad dream time and time again, from the meltdown in October 1987 until the financial catastrophe that erupted in August 2007.

  The flaw had already been identified decades earlier by one of the most brilliant mathematicians in the world: Benoit Mandelbrot.

  When German tanks rumbled into France in 1940, Benoit Mandelbrot was sixteen years old. His family, Lithuanian Jews, had lived in Warsaw before moving to Paris in 1936 amid a spreading economic depression. Mandelbrot’s uncle, Szolem Mandelbrojt, had moved to Paris in 1929 and quickly rose to prominence among the city’s mathematical elite. Young Mandelbrot studied under his uncle and entered a French secondary school. But his life was upended when the Nazis invaded.

 

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