* Gold surges to eight-week high; oil rises on weak dollar
* Tiffany down after weak holiday season sales
* Indexes down: Dow 0.33 pct, S&P 0.39 pct, Nasdaq 0.69 pct (Updates to open)
By Yashaswini Swamynathan
Jan 17 (Reuters) - U.S. stocks fell on Tuesday, with healthcare and financial stocks coming under pressure, as investors assessed President-elect Donald's Trump's comments on the dollar and drug pricing.
The dollar index fell nearly 0.8 percent on Tuesday, after Trump warned that the dollar was too strong, hurting the competitiveness of U.S. companies.
Healthcare stocks took a beating after Trump told Washington Post that he would target pharmaceutical companies over drug pricing.
U.S. stocks and the dollar have rallied since Trump's election on bets that he would usher in an era of economic growth through fiscal stimulus. However, the rally has hit a speed bump as Trump has provided little detail on his policies.
Financials, which have benefited the most in the post-election rally, were off 1.2 percent. Morgan Stanley fell about 1.6 percent after reporting results.
British Prime Minister Theresa May said the country would leave the European Union's single market upon its exit from the group, but that a final Brexit deal would be put to parliamentary vote.
At 9:48 a.m. EDT the Dow Jones industrial average was down 65.33 points, or 0.33 percent, at 19,820.4, the S&P 500 was down 8.81 points, or 0.39 percent, at 2,265.83 and the Nasdaq Composite was down 38.28 points, or 0.69 percent, at 5,535.83.
Gold prices surged more than 1 percent, trading at a near two-month high, while the Japanese yen rose to a six-week high. Oil prices ticked up 1.5 percent, benefiting from the weak dollar.
Tiffany & Co's shares dropped 5.6 percent after the upscale jeweler reported disappointing performance during the holiday season.
Reynolds American were up 3.6 percent at $58 after British American Tobacco agreed to buy its U.S. rival for $49.4 billion.
Declining issues outnumbered advancers on the NYSE by 1,474 to 1,311. On the Nasdaq, 1,766 issues fell and 761 advanced.
The S&P 500 index showed four new 52-week highs and one new low, while the Nasdaq recorded 27 new highs and six new lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Anil D'Silva)