* Futures: Dow down 21 pts, S&P down 2.25 pts, Nasdaq up 0.75 pts
By Yashaswini Swamynathan
Jan 9 (Reuters) - U.S. stock index futures were slightly lower as oil prices dipped on Monday, after the Dow Jones Industrial Average came tantalizingly close to 20,000 on Friday.
* The Dow hit 19,999.63 points on Friday after a late pop in Apple and other technology stocks. Wall Street has rallied since Donald Trump won the U.S. election in November as investors bet he will stimulate the economy with lower taxes and infrastructure spending.
* But the rally has led to lofty valuations - the S&P 500 is trading at about 17 times expected earnings, compared to its 10-year average of 14. That could make investors cautious as they gear up for the fourth-quarter earnings season.
* The first peek into how companies fared last quarter will be provided later this week by big U.S. banks, including JPMorgan, Bank of America and Wells Fargo .
** S&P 500 companies overall are expected to post a 6.1 percent increase in profit in the quarter, according to Thomson Reuters I/B/E/S.
* Oil prices fell 1.8 percent on Monday as signs of growing U.S. production outweighed optimism that other producers were sticking to a deal to cut supplies in a bid to bolster prices.
* Meanwhile, investors looking for more insight on the future path of interest rates await a speech at 9:00 a.m. ET (1400 GMT) by Eric Rosengren, president of the Boston Federal Reserve bank.
* Atlanta Fed President Dennis Lockhart is scheduled to speak later in the day.
* Merrimack's shares rose more than 40 percent to $5.06 premarket after the company agreed to sell its oncology assets to France's Ipsen SA in a deal worth about $1 billion.
* Vertex Pharma lost 5.2 percent to $75.25 after the company gave a full-year revenue forecast for its Orkambi cystic fibrosis treatment, which an Evercore ISI analyst said appeared to miss analysts' expectations.
Futures snapshot at 6:54 a.m. ET:
* Dow e-minis were down 21 points, or 0.11 percent, with 12,708 contracts changing hands.
* S&P 500 e-minis were down 2.25 points, or 0.1 percent, with 60,650 contracts traded.
* Nasdaq 100 e-minis were up 0.75 points, or 0.01 percent, on volume of 12,419 contracts. (Reporting by Yashaswini Swamynathan in Bengaluru; Editing by Savio D'Souza)