The markets closed flat with the Dow adding 6 points to 17,489 as a drop in home builder confidence tempered enthusiasm for an upbeat factory output report. Nasdaq edged up a point to 4,986.

On the upside

Air Liquide offered a premium of approximately $10.3 billion in cash to acquire Airgas (NYSE: ARG).

Monsanto (NYSE: MON) may make another bid for Syngenta (NYSE: SYT).

Shares of Harvard Apparatus Regenerative Technology (Nasdaq: HART) rose again.

On the downside

Lakewood Capital Management analyst Anthony Bozza said that investors should short Universal Insurance Holdings (NYSE: UVE).

Vivint Solar (NYSE: VSLR) swung to a profit for the third quarter but shares of the solar energy distributor plunged on SunEdison's (NYSE: SUNE) woes. Vivint will be acquired by SunEdison for approximately $2.2 billion.

Brean Capital downgraded Osiris Therapeutics (Nasdaq: OSIR) from a Hold rating to a Sell rating.

In the broad market, declining issues outpaced advancers by a margin of more than 5 to 3 on the NYSE while advancers edged out decliners by nearly 5 to 4 on Nasdaq. The broader S&P 500 slipped 2 points to 2,050. Bitcoin climbed $7 to $334.