Stocks marched to another day of gains, with the S&P 500 crossing 2,000 for the first time but pulling back from its intraday record high of 2001.94 to spend the rest of the session stuck just below the 2K mark.
The milestone came on an otherwise quiet day for stocks, but "less news is good for this market," said First American Trust chief investment officer Jerry Braakman.
Investors remained focused on comments from ECB President Draghi, who suggested a willingness for more aggressive stimulus.
Roche's deal to acquire interMune helped propel the top biotech ETF to its best level since February.
Trading volume remains "incredibly low," as the 482M shares traded on the NYSE floor represented the lowest total of the year; last Friday marked the previous low.
Treasurys ended with modest gains, as the 10-year yield slipped 2 bps to 2.39%.