"“Keynes’s experience shows how difficult currency speculation is,” Mr. Chambers said. “He was trading his own money and he understood what he was doing. He was able to absorb losses. Some hedge funds are trying to do this stuff and live hand-to-mouth on a quarter-to-quarter basis, and that’s really difficult to do. Keynes was also an active investor in the stock market, and in the 1920s tried to time stock picks. But his returns were low, and he took a big hit in the market crash of 1929."
Some argue that the long-term equity investment was driven by inside-information that he received from his contacts in government and business. That may be unfair.