Activist investor Elliott Management said on Friday it has invested more than $1.5 billion in Aspen Technology, opposing the company's decision to accept Emerson Electric's $7.2 billion tender offer.

Merger-arbitrage traders are piling into bets that the emergence of Elliott Investment Management as an investor in Aspen Technology Inc. will result in a higher buyout bid from the company’s majority holder Emerson Electric Co.

Emerson Electric's $265 per share tender offer for Aspen Technology is labeled as its best and final price despite criticism from Elliott

Elliott Investment Management has emerged as the largest minority investor in industrial-software company Aspen Technology Inc., with a position worth more than $1.5 billion, people with knowledge of the matter said.

With a more than $1.5 billion Emerson holding, Elliott has claimed that the $265-per-share offer undervalues Aspen Tech and is advocating a larger proposal. Mark Schappel, a Loop Capital analyst, said Elliott is probably going to persuade enough minority investors Aspen Tech is worth far more than Emerson's current offer.

Activist investor Elliott Investment Management said on Friday it doesn’t agree with the price offered by Emerson Electric to acquire Aspen Technology, Inc. and considers it highly opportunistic. In late January,