US STOCKS-Wall St ends up sharply as investors buy beaten-down shares

(Corrects paragraph 13 to say vehicle sales for Ford and GM stronger than expected)

* Gilead leads as biotechs end 5-day losing streak

* Railcar makers gain on new tough oil-train safety rules

* Social media stocks underperformers for week

* Indexes up: Dow 1 pct, S&P 1.1 pct, Nasdaq 1.3 pct

By Caroline Valetkevitch

May 1 (Reuters) - U.S. stocks bounced back sharply on Friday as investors snapped up beaten-down shares in the healthcare and technology sectors, and as data gave further signs of a pickup in the economy.

Apple (NasdaqGS: AAPL - news) provided the biggest boost to the major indexes, jumping 3 percent to $128.95 in its biggest daily percentage gain since January. The stock lost 2.7 percent on Thursday.

The Nasdaq snapped a four-day losing streak while the S&P tech sector gained 1.5 percent, among the day's best-performing sectors.

Biotech shares also rebounded, ending a five-day losing streak. The Nasdaq Biotech Index was up 2.9 percent for the day, but lost 5.5 percent for the week, its worst such decline since March 2014.

Shares (Berlin: DI6.BE - news) of Gilead rose 4.5 percent to $105.01, helping to lift both the Nasdaq and S&P 500, after its quarterly profit nearly doubled. The S&P healthcare index was up 1.3 percent.

Investors were also buoyed by an encouraging batch of data for April that suggested the U.S. economy was pulling out of a first-quarter soft patch.

"Yesterday people were thinking the market was going to fall off of a cliff, and today we're seeing a lot of institutional buying coming in," said Adam Sarhan, chief executive of Sarhan Capital (Other OTC: CGHC - news) in New York.

"So, the buy-the-dippers show up and defend the market. That leads me to believe there's more upside."

Indexes posted losses for the week, however, with social media shares among the weakest performers following disappointing outlooks and results this week from several key players including Twitter (Xetra: A1W6XZ - news) .

The Dow Jones industrial average rose 183.54 points, or 1.03 percent, to 18,024.06, the S&P 500 gained 22.78 points, or 1.09 percent, to 2,108.29 and the Nasdaq Composite added 63.97 points, or 1.29 percent, to 5,005.39.

LinkedIn, Twitter and Yelp (NYSE: YELP - news) all notched their biggest weekly percentage declines since their debuts. LinkedIn, which reported results late Thursday, dropped 18.6 percent to $205.21.

For the week, the Dow was down 0.3 percent, the S&P 500 was down 0.5 percent and the Nasdaq was down 1.7 percent.

Consumer sentiment jumped and vehicle sales for GM (NYSE: GM - news) and Ford were stronger-than-expected in April, while manufacturing expansion in the month held steady at near a two-year low.

Railcar makers gained after tougher oil-train safety standards, including rules to phase out older tank cars in three years, were announced.

Greenbrier gained 8 percent to $62.33, while Trinity (HKSE: 0891.HK - news) Industries rose 6.9 percent to $28.96. American Railcar was up 5.9 percent at $56.18.

Advancing issues outnumbered declining ones on the NYSE by 1,850 to 1,201, for a 1.54-to-1 ratio on the upside; on the Nasdaq, 1,664 issues rose and 1,118 fell for a 1.49-to-1 ratio favoring advancers.

The benchmark S&P 500 index posted 10 new 52-week highs and no new lows; the Nasdaq Composite recorded 35 new highs and 69 new lows.

About 6.3 billion shares changed hands on U.S. exchanges, compared with the 7.2 billion daily average for the last five sessions, according to data from BATS Global Markets.

(Additional reporting by Tanya Agrwal; Editing by Savio D'Souza and Meredith Mazzilli)