Exxon purchases Pioneer for $253 per share, but Pioneer is trading at $269

The sale was announced back in October:

Exxon Mobil Corporation (NYSE: XOM) and Pioneer Natural Resources (NYSE: PXD) jointly announced a definitive agreement for ExxonMobil to acquire Pioneer. The merger is an all-stock transaction valued at $59.5 billion, or $253 per share, based on ExxonMobil’s closing price on October 5, 2023. Under the terms of the agreement, Pioneer shareholders will receive 2.3234 shares of ExxonMobil for each Pioneer share at closing. The implied total enterprise value of the transaction, including net debt, is approximately $64.5 billion.

But why is Pioneer (PXD) trading at higher than the sales price? Is it because people think Exxon shares will go up in value?

I'm thinking about selling my PXD shares (got in at $245/s). Any good oil stocks you guys like with high dividends?