Meme Stocks and Market Structure

Unless your investment horizon is measured in milliseconds, it’s usually best to ignore what everyone else is doing. But, occasionally, the market throws up something so peculiar that you have no choice but to sit up and pay attention.

The GameStop debacle, and the meme stock phenomenon more broadly, certainly fit that category. The story bears all the hallmarks of a Hollywood script: how a ragtag group of mostly retail investors, armed with commission-free trading apps and loosely coordinated across online message boards, executed a colossal short squeeze on the hedge funds betting against a down-at-its-heels brick-and-mortar video game retailer while inflicting bloody noses on some of Wall Street’s supposedly most-sophisticated operators. Predictably, several films are already in the works. But beyond the thrill of extravagant market pyrotechnics served up with a generous side of schadenfreude at seeing the odd master of the universe brought low by the great unwashed, why should we care?

Market manipulation is hardly new, and short sellers have always been a vulnerable target. The algebra of short selling, where the size of a losing position balloons ever higher as losses accumulate, is such that short sellers are forever in danger of being squeezed. Wait too long to cover or, worse yet, fail to rebalance at all, and you risk being wiped out. No surprise then that short selling for profit (as opposed to for hedging) is the province of dedicated specialists.

Despite their somewhat louche reputation, attested to by the prevalence of short-selling bans that reflexively blossom every time the market wilts, short sellers are nonetheless a key part of a healthy market ecosystem. A healthy market, one that allocates capital to its most productive use at the lowest possible cost, is predicated on many financial species with different time horizons, preferences, and liquidity needs co-existing in symbiosis. Despite what the textbooks might say, liquidity and price discovery are not created in a vacuum; they spring from the unceasing dance between three types of market inhabitants: long-term investors, arbitrageurs, and liquidity providers. Long-term investors attempt to steer capital towards its most productive use, arbitrageurs improve price discovery by correcting the occasional mis-pricings that emerge between assets with similar payoffs, and liquidity providers lubricate transactions, which helps to shrink transaction costs. If any one of these groups grows too dominant, the dance can quickly turn into a scrum.

It may be too early to add dedicated short selling to the long list of business models disrupted by the internet just yet, but it’s safe to assume that the shorts’ cost of capital has gone up.

Dedicated short sellers are a rare breed of arbitrageur whose relatively small number and modest asset base belie their importance. Much like value investors, whose tendency to buy when others are selling has a stabilizing effect on falling markets, short selling has a similar calming effect in the opposite direction. By leaning against unwarranted price increases, short sellers are a counterweight to market excess, one that makes for a more hospitable environment for beta grazers and alpha hunters alike. In helping to expose flimsy business models, ferret out accounting malfeasance, and unearth cases of outright fraud, short sellers are natural predators that benefit the market’s ecology. Enron, Lehman Brothers, Valeant, and, more recently, Wirecard and Luckin Coffee all owe their comeuppance in large part due to the sleuthing of dedicated short sellers.

Although short sellers are at the center of the GameStop saga, most of the ink spilled has focused on the more conspicuous elements of the story: the evident power of massed retail investors, their copious use of derivatives to magnify leverage, and the populist tendencies that seemingly motivated many of the squeeze’s participants. What has received less coverage is the potential impact of meme stock manias on market structure.

On the face of it, the debacle mirrors many previous episodes of market manipulation, no different, say, than the Hunt brothers ill-fated attempt to corner the silver market in 1980. But there is a crucial difference. A conspiracy to manipulate markets pre-supposes a central origin, a mastermind to hatch the plot before putting it into action. But on this occasion the conspiracy, such as it was, emerged spontaneously. It began with local, seemingly random interactions online that began to feed on themselves in an accelerating feedback loop.

There was no syndicate head, no directives whispered into disposable cell phones, no encrypted texts, none of the subterfuges typically associated with a conspiracy. Quite the contrary, discussions were held in the open, within freely accessible (albeit anonymous) web forums, where anyone was able to proffer their views about the fundamental value of the business, comment on the high short interest, or add an opinion about the implications of the tight float of underlying shares outstanding.

Decentralized and self-organizing short squeezes that materialize spontaneously represent a new type of concern for regulators because it’s unclear which rules, if any, are being violated. Moreover, it’s far from clear what mechanisms can be put in place to prevent it from happening again. But while this may be a headache for regulators, it represents an existential threat to short sellers. It may be too early to add dedicated short selling to the long list of business models disrupted by the internet just yet, but it’s safe to assume that the shorts’ cost of capital has gone up.

The impact of this new regimen on short sellers is impossible to gauge with any precision. They are a secretive bunch, after all. But we can guess at their travails by looking at the performance of the most shorted stocks as represented by the Citibank US Short Interest Equity Index. The index is akin to a long/short portfolio constructed according to the level of short activity for each stock in the Russell 3000, measured as the ratio of the amount of stock on loan relative to its overall trading volume. After ranking stocks according to this ratio and removing stocks with the most extreme metrics such as high borrow cost, the index simply shorts the 10 percent of stocks with the highest short ratio and goes long the 10 percent of stocks with the lowest short ratio. Historically, simulating short sellers in this way has been a profitable strategy: from its inception in June 2015 through the end of 2019 the index generated a cumulative return of 35%, with a highly respectable return to risk (Sharpe ratio) of close to one. At the onset of the pandemic in early 2020, which coincided with a jump in retail trading reminiscent of the tech bubble, the index collapsed. Over the following months it gave up almost its entire accumulated historical performance before reaching its nadir in January of this year, just as the GameStop episode reached its crescendo. Given the index’s long exposure to the least-shorted stocks, it likely understates the actual damage inflicted on many actual short sellers.

Source: Bloomberg

It’s a truism that no one enjoys losing money, ever. And if the performance of the index is indicative of the damage inflicted on short sellers, we can expect an imminent thinning of their ranks and with it a weakening of their stabilizing influence.

There is a small town in Thailand whose large population of macaque monkeys draws a steady stream of tourists. The locals sell bananas to the tourists who feed them to the monkeys. When the flow of tourists dried up during the pandemic, this balance was thrown into turmoil. Within weeks, the town was overrun by gangs of starving monkeys. Whole neighborhoods were declared no-go areas by authorities after videos of rampaging monkeys went viral.

It’s probably a stretch to claim that having fewer short sellers would have quite such a dramatic impact on market structure as the loss of tourists had on this Thai town, or that the monkeys are now calling the shots, but markets are notoriously susceptible to unforeseen events. A seemingly inconsequential disturbance in one area can ripple out, propagating and growing until it ultimately leads to systemwide effects. While our attention is often drawn to conspicuous price movements, it’s easy to overlook the veiled institutional or structural changes that sometimes precede and may even precipitate them. Bananas, anyone?

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