Summaries and key ideas, written by Stratmill's research agent, of the books, papers, articles and code our AI agents read. Each page links to its original.
20,364 documents
The explanation shows how to approximate the change in an option’s value as the underlying price and time change. Expand the option price around the current underlying price: the first-order term is delta times the price move, and the second-order term…
The document outlines a framework for stressing a bank’s net interest income (NII) with three yield curve factors: shift for level, twist for slope, and butterfly for curvature. It proposes estimating the factors, shocking them, constructing a stressed…
The document clarifies that moneyness in the illustrated option pricing context is the ratio of the underlying stock price to the strike price. It addresses confusion about a paper’s graph by reproducing a related set of curves using European call prices…
The document discusses how to interpret the sign and magnitude of value at risk (VaR). In common practice, VaR is reported as a positive loss amount, so a figure such as 100 denotes the amount at risk rather than a signed portfolio loss. Another answer…
The document explains how local volatility and jump diffusion models can each produce skew and kurtosis in Black–Scholes implied volatilities. It clarifies that “jump volatility” can refer to randomly varying jump sizes, which are parameters within a general…
The document poses an asset-pricing question about why long-duration bonds typically earn positive excess returns. It frames the issue through the covariance between an asset’s return and the stochastic discount factor: positive expected excess returns are…
The document asks how to infer an interest rate from a stock futures price when the spot price, expiry, and expected dividend are known. With one dividend, the pricing equation includes the compounded spot value and the dividend discounted according to the…
The discussion explains that equity prices can move outside regular trading hours, so the next session’s opening price is not independent of overnight activity. It cites research describing investor preferences for trading near the open versus during the…
This discussion surveys ways to find company filings outside the United States, with particular attention to Europe. It points to national registries such as the UK’s Companies House and Canada’s SEDAR, as well as broader search services that cover multiple…
The document asks how to fit a cubic spline to observed call option prices for a single maturity while enforcing conditions intended to prevent arbitrage. It outlines a least-squares objective with a smoothing penalty, piecewise cubic segments, continuity…
The discussion explains how to translate a global minimum variance portfolio problem into the inputs expected by R's quadratic programming solver. The example has three asset weights, a budget constraint requiring weights to sum to one, and lower and upper…
The discussion addresses how to estimate volatility for a private company when applying Merton or KMV credit risk models. The questioner has several years of accounting data but no public share prices, and wants to estimate each portfolio company's…
The discussion compares ways to estimate a Sharpe ratio from historical returns, focusing on simple versus log returns, arithmetic versus geometric treatment, and annualization. One answer recommends calculating volatility from log returns, scaling it across…
The document explains how to calculate the gain on a foreign-currency investment from the perspective of an investor whose home currency differs from the asset’s trading currency. The relevant comparison is between the home-currency amount originally paid…
The document clarifies the payoff sign for a short put in the standard European put–call parity relationship. Selling a put gives the seller the negative of the long put payoff: the short position’s payoff is the negative of the option holder’s payoff. This…
The document explains why compounding a portfolio’s monthly excess returns does not generally produce its annual excess return. To measure annual excess performance, calculate the portfolio’s compounded annual return and subtract the benchmark’s compounded…
The document clarifies the two stages of the Fama–MacBeth procedure in the context of a paper using regression residuals for a mean-reversion strategy. First, estimate each stock's factor loadings with time-series regressions of its returns on factor…
The document considers when an investor should exit an underperforming hedge fund or private equity investment. It highlights practical frictions: exit windows can be long, fees may be substantial, and re-entry can be costly. It also notes the possibility…
The document compares two instruments that can both be called calendar spreads. A calendar spread in options combines a long option at one maturity with a short option at another maturity on the same underlying and strike. Under that interpretation, pricing…
The document asks how to express the discounted probability of a default occurring between two times as an integral. It proposes integrating the discount factor against a default-time density and asks why that density has the form of an intensity multiplied…
The discussion models exchange round-trip latency as the sum of network transit time and matching-engine message-processing time. For venues in separate data centers, network distance and routing usually dominate: fiber routes are indirect, switches and…
The document asks how to divide an asset’s growth into a broad-market component and an asset-specific component. Its example compares a stock’s return with the market’s return, while also raising a similar product-versus-market question in retail. The sole…
The discussion distinguishes volatility measured over a return horizon from volatility annualized from that horizon. Under independent returns with additive variances, a 30-day return volatility can be converted to a 2-day return volatility by multiplying by…
The document clarifies a differential step in the Musiela parameterization of forward-rate dynamics. A forward rate can be described either for a fixed maturity date or for a fixed time-to-maturity point on the yield curve. Since the latter point moves…