Shares of NetSuite's stock rose as much as 8 percent on Thursday, following a volatility halt earlier in the day.
Oracle offered to buy Netsuite for $9.3 billion earlier this year, a move that would combine Netsuite's software with Oracle's growing cloud business. But the offer expires on Thursday night, according to Barron's, which reports the deal has about a 63 percent chance of going through.
The stock pared its gains, but still ended the day 5 percent higher at $94.
CNBC has reached out to NetSuite on the status of the deal. Oracle declined to comment.
But Oracle CEO Mark Hurd told CNBC last week that Oracle's board had made its "best and final offer" to NetSuite.
"We'll abide by what the shareholders say," he told "Closing Bell." "If the shareholders don't want to tend to their shares, we'll move on to other things."
NetSuite shareholder T. Rowe price has pushed Oracle to pay $133 a share for NetSuite, up from the $109 a share originally offered.
"[Mergers and acquisitions] can be harrowing and uncertain, and typically is in motion until the last minute, with both parties often appearing stalled during the tender process," Macquarie Capital analyst Sarah Hindlian wrote of the deal last week. "Therefore, though these headlines may suggest a deal is unlikely, we caution that such headlines should be expected. We believe that both parties may still come to the table before the 11/4 tender offer deadline."
— CNBC's Antonio Jose Vielma contributed to this report