By Ryan Vlastelica
NEW YORK (Reuters) - U.S. stock index futures were little changed on Monday, with investors finding few reasons to keep pushing shares higher with the Dow and S&P 500 at record levels.
* Equities have been strong performers lately, with the Dow and S&P ending their fourth straight monthly rise in May and the Nasdaq up for its third straight week last week. However, those gains have recently come on anemic volume, a trend that looks to continue Monday, suggesting the rise lacks conviction.
* Wall Street investors continue to closely watch U.S. Treasury yields. The 10-year note's yield remains below 2.5 percent, near an 11-month low hit during Thursday's session. Low yields could help boost dividend-paying stocks, including in the telecom and utility sectors.
* The CBOE Volatility index continues to hover around lows not seen since March 2013. That the so-called "fear index" is so low has many, including officials at the Federal Reserve, concerned the market is complacent.
* S&P 500 futures rose 1.2 point and were above fair value, a formula that evaluates pricing by taking into account interest rates, dividends and time to expiration on the contract. Dow Jones industrial average futures added 16 points and Nasdaq 100 futures rose 4 points.* Roughly 72,500 S&P 500 e-mini contracts traded as of 7:00 a.m. (1100 GMT), suggesting limited action on Monday. Trading may be light until the European Central Bank's June 5 meeting. Many investors anticipate the ECB will announce a loosening of monetary policy at the meeting.
* Ariad Pharmaceuticals Inc was the Nasdaq's most active premarket mover, jumping 17 percent to $7.55 on heavy volume a day after saying its drug ponatinib showed anti-tumor activity in patients with advanced gastrointestinal stromal tumors.
* Pharmacyclics Inc rose 7.1 percent to $95.10 in light premarket trading after late-stage study findings showed that its drug Ibrutinib, which treats the most common form of leukemia in adults, improved survival for patients whose disease had worsened despite standard treatment. Pharmacyclics sells the drug with Johnson & Johnson.
* In deal news, Japanese insurer Dai-ichi Life Co is in advanced talks to buy Protective Life Corp in a deal that could be worth over $5 billion. Late Friday, Valeant Pharmaceuticals International Inc said it would boost its takeover bid for Allergan Inc for the second time in a week, lifting it to $53.8 billion from $49.9 billion.
(Editing by Bernadette Baum)