James Steven Chanos (born December 24, 1957) is a Greek-American investment manager. He is president and founder of Kynikos Associates, a New York City registered investment advisor focused on short selling. He is known for predicting the fall of Enron before its collapse. He has been nicknamed the "Darth Vader of Wall Street", the "Catastrophe Capitalist", and the "LeBron James of short selling". Chanos is a noted art collector.

James Steven Chanos was born in 1957 into a Greek immigrant family living in Milwaukee, Wisconsin, that operated a chain of dry-cleaning shops. He graduated from Wylie E. Groves High School in Beverly Hills, Michigan. He received a Bachelor of Arts degree, double-majoring in economics and political science from Yale University in 1980.

Chanos began his career at brokerage firm Gilford Securities in 1982. While at Gilford, he performed a cash-flow analysis and made a sell recommendation that ultimately exposed Baldwin-United, which filed for bankruptcy in 1983. Shortly thereafter, Chanos was recruited to Deutsche Bank, where he analyzed Michael Milken's junk bonds and Drexel Burnham Lambert.

After working as an analyst in several firms, Chanos founded Kynikos (Greek for "cynic") in 1985 with $16 million, as a firm specializing in short selling. One critical position he took at Kynikos was the shorting of Enron.

He describes his investment strategy as "intensive research into stocks", looking for fundamental failures in market valuation, from underestimated or unreported failings in the business or the market of a particular stock, followed by a substantial short position which he is willing to hold for quite a long time — perhaps an opposite echo to Warren Buffett's reputed "fundamentals+long stay" investment strategy. Some have said his commitment serves as whistle-blowing more than do most speculations, as in his heavy shortselling of such companies as Baldwin-United and Enron Corporation.

Throughout the 2010s, Chanos and other short sellers faced a tough environment during a booming period for M&A and a record amount of share reacquisitions. A New York Times profile of several short sellers in 2015 described Chanos and others as "waiting in the wings" for the bull market to end. The same profile described Chanos's Kynikos Associates as losing more than half its value in the last five years from $6 billion to $2.5 billion, compelling Chanos to pitch "a new fund to investors that will take a portfolio of long positions and overlay the firm's traditional short portfolio". Chanos's personal net worth in 2016 was estimated at $1.5 billion (equivalent to $2.01 billion in 2025).

2020 was an especially terrible year for Chanos and other short sellers, according to Institutional Investor, calling their firms "a shadow of their former selves." The magazine noted Kynikos ended 2020 with $405 million (equivalent to $504 million in 2025) in assets, compared to $2 billion in 2018.

In November 2023, The Wall Street Journal reported that Chanos would close his hedge fund and return outside capital to investors by the end of the year. At the time of publication, the S&P500 was up nearly 20% year -to-date, and Tesla, a notable short position of Chanos' fund, was up nearly 117%.