Acquirer share price post-merger

Does the acquirer’s share price remain the same post-merger? Does this happen in both cases of paying in cash and paying in shares?

My question came up due to the following question and its answer:

Yellow Inc has just announced that it will acquire Green Inc using a securities offering.
The exchange ratio is 0.9.
Green Inc has 2 million shares outstanding.
On the day of the merger, the share price of Green Inc is $18.00, the share price of Yellow Inc is $23.00.
Fiona Jones is a shareholder in Green Inc, who prior to the acquisition, held 8,500 Green Inc shares. What would be the value of her holding immediately after the acquisition?

After the acquisition Fiona would hold 0.9 x 8,500 = 7,650 shares
The value of 7,650 shares of Yellow Inc shares is: 7,650 x $23 = $175,950