In 2016, Mondelez International failed in its attempt to buy Hershey (HSY 13.29%). Now more than eight years later, Mondelez is reportedly trying again.

According to Bloomberg, Mondelez just approached Hershey in hopes of acquiring it. And that’s why Hershey stock was up 12% as of 1:30 p.m. ET.

Some investors are betting on an acquisition

Back in 2016, Mondelez tried to buy Hershey for $23 billion. Hershey rejected the offer and it’s arguably been a good decision. Since the offer was rejected, Hershey stock is up more than Mondelez stock after factoring in dividends.

HSY Total Return Level data by YCharts

That said, both Hershey and Mondelez are underperforming the S&P 500 during this time. And Mondelez is likely eyeing the opportunity of better returns if it owned Hershey, which would give it greater scale and market presence.

Companies usually need to pay a premium when acquiring another business. And that’s why news of Mondelez’s interest sent Hershey stock higher today. Investors are betting that Mondelez would pay a higher price than where Hershey stock trades now.

Will Hershey agree?

It’s important to note that Bloomberg is merely citing people familiar with the matter — nothing has been announced from either company. Deals often fail to materialize when they start as just a rumor from an anonymous source.

It’s possible that Hershey would be in an agreeable mood right now. After all, business is slow. Management expects sales this year to be flat year over year and its earnings per share could drop by up to 9%. With commodity prices high and consumer behaviors changing, it’s possible that management will agree to let Mondelez take over.

However, I don’t believe that investors should count on Mondelez buying Hershey. Decisions to buy or sell should still be on the merits of Hershey’s business, not the hopes of an acquisition. And in my opinion, Hershey is a stock worth holding on to considering its long history and its unusually low valuation right now.