* Russell 2000, Dow Transport hit record highs
* Dow set for fifth week of gains in a row
* Indexes up: Dow 0.29 pct, S&P 0.3 pct, Nasdaq 0.37 pct (Updates to early afternoon)
By Yashaswini Swamynathan
Dec 9 (Reuters) - Wall Street hit a trifecta of records for the third day in a row on Friday as the month-long post-election rally got a boost from healthcare and technology stocks.
The three main U.S. stock indexes have hit a series of record highs as investors piled into sectors such as banks and industrials, betting that President-elect Donald Trump would usher in a business-friendly environment.
The small cap Russell 2000 and the Dow Transport indexes also hit record intraday highs.
With the rally about to enter its second month, however, valuations may come under focus.
The S&P 500 is currently trading at about 17.5 times forward 12-month earnings, above the 10-year median of nearly 15 times, according to Thomson Reuters StarMine.
"I think if you are a short-term trader, you may be looking to take profits and you are starting to see a little bit of that in financials," said Robert Pavlik, chief market strategist at Boston Private Wealth.
The resilience of the stock market will be put to test after the Federal Reserve's policy meeting next week, where traders expect a 94 percent chance of an interest rate increase.
At 12:25 p.m. ET (1725 GMT), the Dow Jones Industrial Average was up 55.95 points, or 0.29 percent, at 19,670.76, easing from an all-time high of 19,684.06 earlier in the session.
This is the 11th record high for the Dow since the election and the index is set for its fifth week of gains in a row.
The S&P 500 was up 6.63 points, or 0.3 percent, at 2,252.82, after hitting a record of 2,255.06.
The Nasdaq Composite was up 20.09 points, or 0.37 percent, at 5,437.45. The index hit a record high of 5,450.16.
Six of the 11 major S&P 500 sectors were higher, led by a 1.03 percent rise in health stocks and a 0.5 percent rise in technology.
Pfizer rose 2.6 percent and Merck 2 percent, giving the biggest boost the healthcare index.
Other pharma stocks helping the index were Bristol-Myers , which rose 3 percent after raising its quarterly dividend; and Biogen, which gained 4.1 percent following positive data on its Alzheimer's drug.
Financials, which have been the best performers in the rally, were off 0.3 percent.
Broadcom was the top percentage gainer on the S&P, rising 4.9 percent after the chipmaker reported upbeat fourth-quarter results and doubled its dividend.
Coca-Cola rose 2.9 percent and was among the top stocks on the Dow after the company said Muhtar Kent would step down as chief executive and named Chief Operating Officer James Quincey as his successor.
Declining issues outnumbered advancers on the NYSE by 1,542 to 1,312. On the Nasdaq, 1,528 issues rose and 1,226 fell.
The S&P 500 index showed 48 new 52-week highs and no new lows, while the Nasdaq recorded 310 new highs and 11 new lows. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Saumyadeb Chakrabarty and Anil D'Silva)