Two Sigma Investments, LP is a New York City-based hedge fund that uses a variety of technological methods, including artificial intelligence, machine learning, and distributed computing, for its trading strategies.

[10] In July 2014, it was announced that Simon Yates, Citigroup's global head of equity derivative sales and trading, left the bank to join Two Sigma.

[13] In February 2015, Gao pleaded guilty to "illegally accessing and duplicating proprietary and confidential information related to the firm's trading methods.

It seems that relations between co-founders John Overdeck and David Siegel collapsed over the course of the previous years, and they were no longer on speaking terms; yet both continued to own a large segment of the company with no sign of being willing to sell their stake.

The relationship was so contentious that the firm stopped holding all-hands meetings, due to the pair's unwillingness to coordinate and address employees or investors together.

[25] Later in 2023, The Wall Street Journal reported in October 2023 that a senior vice president had made unauthorized changes to Two Sigma's trading models, leading to different-than-expected investment results, prompting the U.S. Securities and Exchange Commission to open an investigation.

Halite is a programming game inviting coding enthusiasts to build smart bots whose goal is to gain control of a virtual grid.

[30] Two Sigma has been noted in the business press for its unusually high rate of return, comparable to its older and more mature competitors D. E. Shaw & Co. and Renaissance Technologies.