His address to congress signalled the Fed will keep raising interest rates to contain inflation.
The month also included a confirmation of a 10-percent correction for the stock market but that was followed by a rebound that made the monthly losses less steep.
"It's helping about a dozen stocks in those industries but has raised the specter of trade wars, and trade wars don't help the stock market".
The indices closed lower for the second consecutive session amid uncertainty about the outlook for interest rates after the US Federal Reserve Chair Jerome Powell seemed to suggest that the central bank may raise rates more than the three times now anticipated.
The S&P 500's wild ride in February ended with the benchmark index falling by the most in two years. It had only four such days past year.
The Dow Jones industrial average dropped as much as 500 points Thursday. For the month, the Dow lost 4.4%, the S&P 500 fell 3.8%, and the Nasdaq lost 1.5%.
SEC CALLING: Overstock.com dropped 5 percent after the online retailer disclosed in a regulatory filing that the Securities and Exchange Commission asked the company last month for information about a $250 million offering by its blockchain subsidiary, tZero, related to digital tokens. Some investors took that as a signal that the Fed may get more aggressive on rate increases, which sent stocks down and Treasury yields higher.
"We have seen some data that in my case will add some confidence to my view that inflation is moving up to target", Powell said. The concerns at one point helped knock the S&P 500 down 10 percent from its record high, set in late January.
Dental products supplier Patterson Companies plunged 23 percent in the first few minutes of trading Thursday after issuing weak quarterly results.
Oil prices continue to drop following a report on Wednesday that showed more crude supplies in inventories last week than analysts expected.
On the commodities front, the April crude contract was down 65 cents to US$60.99 per barrel and the April natural gas contract was up three cents at US$2.70 per mmBTU. Brent crude, the worldwide standard, lost 90 cents to $63.83 a barrel.
The Standard & Poor's 500 index dropped 36 points, or 1.3 percent, to 2,677.
The dollar fell to 105.54 Japanese yen from 106.24 yen late Thursday.
European markets closed mostly lower: London's FTSE 0.1 per cent, Paris closed flat and Frankfurt was 0.3 per cent lower. The euro inched up to $1.2207 from $1.2203, and the British pound slipped to $1.3732 from $1.3771. In Asia, Japan's Nikkei 225 lost 1.6 percent and Hong Kong's Hang Seng rose 0.6 percent.