Lasse Heje Pedersen

Carry Trades and Currency Crashes

This paper documents that carry traders are subject to crash risk: i.e. exchange rate movements between high-interest-rate and low-interest-rate currencies are negatively skewed. We argue that this negative skewness is due to sudden unwinding of carry trades, which tend to occur in periods in which risk appetite and funding liquidity decrease. Funding liquidity measures predict exchange rate movements, and controlling for liquidity helps explain the uncovered interest-rate puzzle. Carry-trade losses reduce future crash risk, but increase the price of crash risk. We also document excess co-movement among currencies with similar interest rate. Our findings are consistent with a model in which carry traders are subject to funding liquidity constraints.

Time Series Momentum

We document significant “time series momentum�? in equity index, currency, commodity, and bond futures for each of the 58 liquid instruments we consider. We find persistence in returns for 1 to 12 months that partially reverses over longer horizons, consistent with sentiment theories of initial under-reaction and delayed over-reaction. A diversified portfolio of time series momentum strategies across all asset classes delivers substantial abnormal returns with little exposure to standard asset pricing factors and performs best during extreme markets. Examining the trading activities of speculators and hedgers, we find that speculators profit from time series momentum at the expense of hedgers.

Securities Lending, Shorting, and Pricing

We present a model of asset valuation in which short-selling is achieved by searching for security lenders and by bargaining over the terms of the lending fee. If lendable securities are di cult to locate, then the price of the security is initially elevated, and expected to decline over time. This price decline is to be anticipated, for example,after an initial public o ering (IPO), among other cases, and is increasing in the degree of heterogeneity of beliefs of investors about the likely future value of the security. The initial price of a securitymay be above even the most optimistic buyers valuation of the securitys future dividends, because of the additional prospect of lendingfees for owners.

Leverage Aversion and Risk Parity

The authors show that leverage aversion changes the predictions of modern portfolio theory: Safer assets must offer higher risk-adjusted returns than riskier assets. Consuming the high risk-adjusted returns of safer assets requires leverage, creating an opportunity for investors with the ability to apply leverage. Risk parity portfolios exploit this opportunity by equalizing the risk allocation across asset classes, thus overweighting safer assets relative to their weight in the market portfolio. In our article, we show that leverage aversion changes the predictions of modern portfolio theory: It implies that safer assets must offer higher risk-adjusted returns than riskier assets because leverage-averse investors tilt their portfolio toward riskier assets to achieve high unleveraged returns, thus pushing up the prices of risky assets and reducing the expected return on those assets. Therefore, safer assets are in relatively low demand and offer high risk-adjusted returns. Consuming the high risk-adjusted returns offered by safer assets requires leverage, which creates an opportunity for investors with the ability and willingness to apply leverage. A risk parity (RP) portfolio exploits the high risk-adjusted returns of safer assets in a simple way—namely, by equalizing the risk allocation across asset classes and thus overweighting safer assets and underweighting riskier assets relative to their weights in the market portfolio. Although an unleveraged RP portfolio has a lower risk than the market portfolio (and the 60/40 portfolio) owing to the higher allocation to safer assets, the RP portfolio can be leveraged to achieve the same risk as the market portfolio and a higher expected return. Consistent with our theory of leverage aversion, we found empirically that risk parity has outperformed the market over the last century by a statistically and economically significant amount. Indeed, in the United States, an RP portfolio with the same risk as the market portfolio outperformed the market portfolio by about 4 percent a year over 1926–2010. Furthermore, the RP portfolio delivered higher risk-adjusted returns than the 60/40 portfolio in each of the 11 countries covered by the J.P. Morgan Global Government Bond Index over 1986–2010. We performed extensive robustness tests and analyzed the related evidence across and within countries and asset classes. Editor’s Note: The authors are affiliated with AQR Capital Management, LLC, which offers risk parity funds.

Two Monetary Tools: Interest Rates and Haircuts

We study a production economy with multiple sectors financed by issuing securities to agents who face capital constraints. Binding capital constraints propagate business cycles, and a reduction of the interest rate can increase the required return of high-haircut assets since it can increase the shadow cost of capital for constrained agents. The required return can be lowered by easing funding constraints through lowering haircuts. To assess empirically the power of the haircut tool, we study the introduction of the legacy Term Asset-Backed Securities Loan Facility (TALF). By considering unpredictable rejections of bonds from TALF, we estimate that haircuts had a significant effect on prices. Further, unique survey evidence suggests that lowering haircuts could reduce required returns by more than 3% and provides broader evidence on the demand sensitivity to haircuts.

Quality Minus Junk

We define a quality security as one that has characteristics that, all-else-equal, an investor should be willing to pay a higher price for: stocks that are safe, profitable, growing, and well managed. High-quality stocks do have higher prices on average, but not by a very large margin. Perhaps because of this puzzlingly modest impact of quality on price, high-quality stocks have high risk-adjusted returns. Indeed, a quality-minus-junk (QMJ) factor that goes long high-quality stocks and shorts low-quality stocks earns significant risk-adjusted returns in the U.S. and globally across 24 countries. The price of quality – i.e., how much investors pay extra for higher quality stocks – varies over time, reaching a low during the internet bubble. Further, a low price of quality predicts a high future return of QMJ. Finally, controlling for quality resurrects the otherwise moribund size effect.

Low-Risk Investing Without Industry Bets

The strategy of buying safe low-beta stocks while shorting (or underweighting) riskier high-beta stocks has been shown to deliver significant risk-adjusted returns. However, it has been suggested that such “low-risk investing” delivers high returns primarily due to its industry bet, favoring a slowly changing set of stodgy, stable industries and disliking their opposites. We refute this. We show that a betting against beta (BAB) strategy has delivered positive returns both as an industry-neutral bet within each industry and as a pure bet across industries. In fact, the industry-neutral BAB strategy has performed stronger than the BAB strategy that only bets across industries and it has delivered positive returns in each of 49 U.S. industries and in 61 of 70 global industries. Our findings are consistent with the leverage aversion theory for why low beta investing is effective.

Size Matters, If You Control Your Junk

The size premium has been challenged along many fronts: it has a weak historical record, varies significantly over time, in particular weakening after its discovery in the early 1980s, is concentrated among microcap stocks, predominantly resides in January, is not present for measures of size that do not rely on market prices, is weak internationally, and is subsumed by proxies for illiquidity. We find, however, that these challenges are dismantled when controlling for the quality, or the inverse “junk�?, of a firm. A significant size premium emerges, which is stable through time, robust to the specification, more consistent across seasons and markets, not concentrated in microcaps, robust to non-price based measures of size, and not captured by an illiquidity premium. Controlling for quality/junk also explains interactions between size and other return characteristics such as value and momentum.

Early Option Exercise: Never Say Never

A classic result by Merton (1973) is that, except just before expiration or dividend payments, one should never exercise a call option and never convert a convertible bond. We show theoretically that this result is overturned when investors face frictions. Early option exercise can be optimal when it reduces short-sale costs, transaction costs, or funding costs. We provide consistent empirical evidence, documenting billions of dollars of early exercise for options and convertible bonds using unique data on actual exercise decisions and frictions. Our model can explain as much as 98% of early exercises by market makers and 67% by customers.

Sharpening the Arithmetic of Active Management

I challenge William F. Sharpe’s famous equality that “before costs, the return on the average actively managed dollar will equal the return on the average passively managed dollar.” This equality i...