Should investors prefer companies with high profit margins or companies with improving profit margins? Is it better to own an unprofitable company that's getting better, or a profitable company that's getting worse? This post explores these questions by analyzing the profitability growth factor and how it interacts with the profitability and size factors to impact stock performance.

How does a company's profitability affect its stock returns? In this post, I use Alphalens, a Python library for analyzing alpha factors, to investigate the relationship between operating margin, a profitability ratio, and future returns.

When researching fundamental factors, analyzing alpha shouldn't be your first step. You can save time and spot issues early by starting with a basic exploration of your factor's distribution and statistical properties, a process known as exploratory data analysis (EDA). This post looks at operating margin, a profitability ratio, to demonstrate what you can learn from exploratory data analysis.

You may have heard about Python type hints and wondered whether they're relevant to quants or only to professional software developers. In this article, I'll explain how QuantRocket's JupyterLab environment uses type hints to enable better auto-complete and in-editor documentation, and I'll explain when quants should use type hints in their own code.

QuantConnect, a quantitative backtesting and trading platform serving mostly retail traders, recently announced a crowdfunding campaign seeking to raise money from its community of users. The company's associated regulatory disclosures (required by the SEC for equity crowdfunding offerings) reveal that the fundraising is a matter of survival. In this article, I explore what QuantConnect's financial statements reveal about the retail quant trading market.

What happens after stocks suffer large one-day losses? This post finds that the proverbial "dead cat bounce" occurs overnight and is followed by continued losses the next day. Targeting international markets, I explore a trading strategy that aims to profit from the losses that follow a dead cat bounce.

What is survivorship bias, and why should you care about it? This post explains how survivorship bias can trick you into drawing faulty conclusions from your research, and what you need to know to avoid being tricked.

Quantopian announced that it is shutting down its community platform. This doesn’t entirely come as a surprise.

What happens when strong stocks gap down at the open? A well-known trading strategy is to buy the gap, expecting mean reversion. This post uses Zipline to explore down gaps and finds a profitable strategy based on selling, not buying, the gap.

Intraday trading strategies offer great promise as well as great peril. This post explores an intraday trading strategy for crude oil calendar spreads and highlights the impact of transaction costs on its profitability.