Shares in Singapore-based Sembcorp Marine jumped as much as 4.6 percent to S$2.50 on Tuesday morning.
The stock gained nearly 20 percent last week and added another 4 percent on Monday amidst speculation including a potential privatization or divestment by parent Sembcorp Industries.
OCBC Investment Research said should an offer for Sembcorp Marine materialize, there could still be some upside as the offer price is usually higher in such cases to lure shareholders.
"Assuming a 20 percent premium from current levels, this would translate to about $2.76 a share," OCBC said.
OCBC has been valuing SembMarine at 1.85 times book but had earlier trimmed the book to be conservative after Keppel Corp's $590 million fine.
At 0525 GMT, Sembcorp Marine shares were up 3.8 percent at S$2.48. About 11 million shares changed hands compared to a 30-day average volume of about 8 million shares.
The sudden spike in share price prompted Singapore Exchange to issue a trading query. The company is yet to respond to it.
SembCorp Marine offers integrated marine and offshore engineering services. The company provides rig building, offshore conversion, repair and maintenance services, offshore platforms and other related marine services. SembCorp Marine serves oil companies, drilling contractors, and shipping companies around the world.