JPMorgan Chase launches a stock market rally

NEW YORK — Strong earnings from JPMorgan launched a stock market rally that gave the Dow Jones industrial average its best day this month.

The Dow jumped 204 points, snapping a six-day slump, to close Friday at 12,777.

JPMorgan surged 6 percent, the biggest gain in the Dow by far. The country’s biggest bank earned $5 billion in the most recent quarter, easily beating Wall Street’s forecasts, even as the loss from a derivative trade grew to $5.8 billion.

In other trading, the Standard & Poor’s 500 index rose 22 points to 1,357 and the Nasdaq composite index gained 42 points to 2,908.

The gains were broad. Five stocks rose for every one that fell on the New York Stock Exchange. Trading volume was below average at 3.1 billion.