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 document considers how to project a sparse monthly series over a one-year horizon when only two years of history are available. The measure is described as a person’s skill, but the suggested modeling considerations also apply to short time series more…
The document raises a theoretical question about whether a positive equity risk premium could arise from a finite investable asset universe, even without investor risk aversion. It contrasts limited diversification in finite markets with a hypothetical…
The document discusses which instruments should be used to build a swaption volatility surface when calibrating to a particular underlying swap. The answer recommends matching the swaption underlying to the swap being calibrated, so that the forward rate…
The document addresses how to describe one asset’s volatility in relation to a portfolio that contains several correlated assets. The answer identifies the quantity as the asset’s marginal volatility contribution and expresses it as the asset’s own standard…
The document raises practical questions about valuing a put option on a Eurodollar futures contract. It considers how a futures price move affects the option’s payoff, how to calculate breakeven from strike and premium, and how the option’s quoted minimum…
The document gives a closed-form expectation for a call or put payoff when the log of the underlying price follows a normal distribution. A sign indicator selects the option type, while the expression uses the normal cumulative distribution function to…
The document explains purging in financial machine learning through a prediction task that uses current stock returns to forecast the next day’s market return. The accepted answer illustrates the issue with a label based on a multi-day future return: labels…
The document addresses how to make a long exchange-rate history comparable when a currency has been redenominated more than once. It treats each redenomination as a scale change, similar to adjusting historical prices for a reverse stock split. If official…
The document explains why a commonly quoted All Weather allocation may not show equal risk contributions when measured with portfolio software. According to the accepted answer, the weights came from an interview describing an unleveraged sample portfolio…
The document asks whether stocks with lower historical return standard deviation tend to earn higher future returns, and whether this finding is broadly established. It distinguishes this measure from idiosyncratic volatility and cites two studies that…
The document considers rolling Shannon entropy of intraday returns and asks how histogram bin size affects comparisons over time. Its answer suggests mutual information when the goal is to measure dependence between variables, with normalization by its…
The document distinguishes volatility in an asset’s price from volatility in its measured returns. Volatility, calculated as the standard deviation of observations, is zero when every observation in the chosen data series is identical. Thus, if the…
The document explains why annualizing volatility from simple returns depends on the model and the quantity being estimated. For a lognormal price model, convert each simple return to a log return by taking the logarithm of one plus the return, then estimate…
The document explains why a European option on an arithmetic basket of correlated stocks generally lacks a direct Black–Scholes formula under geometric Brownian motion: the basket is a sum of lognormally distributed prices, which is not itself lognormal. It…
The document explains why corporate debt can affect both equity value and volatility. In discounted cash flow valuation, interest costs can raise the cost of capital; in a structural view, equity behaves like a call option on company assets, so leverage…
The document asks which swap leg is priced first when structuring a new interest rate swap with zero net present value at inception. It considers two equivalent ways to frame a quote: specify a desired fixed rate and ask what floating payments correspond to…
The document discusses how delayed sell-side earnings revisions can distort valuation signals. After a sharp stock decline, stale forecasts may make a company look unusually cheap; after a market crash, stale aggregate estimates may likewise suggest the…
The document raises a pricing issue for an interest rate swap whose floating leg averages rates observed daily during each accrual period. The payment is based on the average of forward rates for short intervals, discounted to the payment date. Since…
The document considers how to hedge an obligation to buy an asset under a forward contract at a future date. Buying a put with a strike equal to the forward purchase price establishes a floor on the value obtainable by selling the asset, but it requires…
The discussion examines whether delta hedging an option position always reduces risk. A short-dated, out-of-the-money put illustrates a losing path: the underlying falls but stays above the strike, so the option expires worthless while the short underlying…
The document asks how to interpret a test for anticipation effects in a Difference-in-Differences study. It distinguishes this concern from the parallel-trends assumption, which the author describes as commonly assessed by jointly testing whether lead…
The document considers whether it is reasonable to average correlation matrices estimated from the same underlying prices but sampled at different return frequencies. Its answer indicates that this practice has been observed in risk modeling, including…
This document asks how to interpret Fama–MacBeth regressions used to assess whether a six-factor asset-pricing model predicts expected returns. It contrasts a single-factor specification, where the average intercept and market slope are reported as…
The document describes a practical challenge in fitting an oil options volatility surface when market data are uneven across maturities. Near-dated contracts are liquid and screen-based, while longer-dated quotes are broker-based. At-the-money levels toward…