Wall Street's S&P healthcare index rose 1 per cent overnight, hitting its fifth consecutive record close following the release of Senate Republicans' bill to replace Obamacare, while financial and consumer staple shares ended lower.

The legislation aims at curbing Medicaid funding and reshaping subsidies to low-income people for private insurance. US healthcare stocks have now risen 3.9 per cent as a group in five days.

The Nasdaq biotechnology index rose 1.3 per cent, for a 9.4 per cent jump so far this week. While it was not clear whether the bill would get enough support to become law, drug stocks were among the S&P 500's biggest gainers, with Gilead rising 4.4 per cent overnight.

"The initial proposal I think is more generous and more positive to the industry than expected," said Jeff Jonas, portfolio manager with Gabelli Funds.

The Dow Jones gave up early gains to end down 0.1 per cent. The S&P 500 lost a similar amount, while the Nasdaq Composite inched higher.

The S&P energy index ended down 0.1 percent after recording 3.5 per cent of losses in the previous three sessions on falling oil prices.

"Oil's had a tough run in the last handful of weeks. I wouldn't say oil being up today gives anybody a high degree of confidence we've seen a floor in oil yet," Michael Scanlon, managing director, portfolio manager at Manulife Asset Management in Boston.

Thursday's gains were muted as and investors looked forward to the second-quarter earnings season.

"US equities are trading at somewhat rich valuations," said Jason Pride, director of investment strategy at Glenmede in Philadelphia. "With earnings coming up that should provide upside pressure to stocks, but the valuations provide a counterbalance to that."

Economic data overnight showed jobless claims for last week increased by 3,000 to 241,000, but remain at levels consistent with a tight labor market.

Oracle's 8.6 per cent riseprovided the S&P with its biggest boost after the company forecast an upbeat current-quarter profit.