Wall Street closed out the trading week on a high note on Thursday as the US Federal Reserve unleashed another program designed to buoy local governments and businesses crushed by massive closures to stem the coronavirus outbreak.

The benchmark S&P 500 index posted it best weekly gain since 1974, in a holiday-shortened week, bolstered by early signs that the outbreak was hitting a peak as well as aggressive global stimulus.

Under the Fed's $2.3 trillion package, the US central bank said it would work with banks to offer four-year loans to companies of up to 10,000 employees and directly buy bonds of states and more populous counties and cities.

"Buying junk bonds, oh my god, pretty much unexpected, so a very strong open, and all the beaten-up names, including energy, they took off," said Tim Ghriskey, chief investment strategist at Inverness Counsel in New York.

The financial index was up 5.19%, providing the biggest boost to the S&P 500, as banks rose sharply on the Fed's backstop. J.P. Morgan rose 8.97%, leading gains on the Dow. Shares of the iBoxx High Yield Corporate Bond Fund climbed 6.55%.

That helped take the sting out of another tough report on the labor market, with weekly initial jobless claims topping the 6 million mark for a second straight week.

"Everyone is expecting really lousy earnings and really lousy economic data. It is all going to be focused on when does the rebound happen and what parts of the economy comes back the quickest," said Ghriskey.

The defensive real estate and utilities sectors rose more than 4%.

The Dow Jones Industrial Average rose 285.8 points, or 1.22%, to 23,719.37, the S&P 500 gained 39.84 points, or 1.45%, to 2,789.82 and the Nasdaq Composite added 62.67 points, or 0.77%, to 8,153.58. For the week, the Dow rose 12.7%, the S&P climbed 12.1% and the Nasdaq gained 10.6%.

While public health experts stressed the need to keep people apart to contain the contagion, the restrictions have strangled the economy and sparked widespread production cuts, layoffs and projections of a severe recession.

In a sign that the disease's curve was flattening in New York, the epicenter of the US outbreak, Governor Andrew Cuomo said new hospitalizations fell to a fresh low of 200 for the criis, although deaths spiked to another new high.

The three major indexes, however, finished well off their earlier highs as oil prices reversed course and turned lower as production cuts by OPEC and its allies were seen as not enough to offset the lack of demand. The energy sector fell 1.08%.

Walt Disney Co jumped 3.39%, as the company said its Disney+ streaming service had attracted more than 50 million paid users globally.

Advancing issues outnumbered declining ones on the NYSE by a 6.05-to-1 ratio; on Nasdaq, a 3.54-to-1 ratio favored advancers.

The S&P 500 posted six new 52-week highs and no new lows; the Nasdaq Composite recorded 14 new highs and 11 new lows.

Volume on US exchanges was 11.52 billion shares, compared to the 15.1 billion average for the full session over the last 20 trading days.