Do I get anything extra for staying on through a rocky transition period?

Not automatically — there's no general legal rule entitling you to extra pay simply for continuing to show up and do your job during a business sale, even though the period can genuinely be more stressful and demanding than usual. Whether you get anything extra depends entirely on whether the seller or the new owner chooses to offer something, most commonly a retention bonus, a transition allowance, or a one-time payment tied to staying through closing or a set period afterward — none of which the law requires, but many employers offer as a practical way to keep key staff from leaving during a vulnerable period for the business.

If you're taking on genuinely extra duties during the transition, additional hours, expanded responsibilities, training a replacement on top of your regular job, that's worth raising directly, since a request for additional compensation tied to real extra work is a reasonable thing to ask for, even if it isn't guaranteed.

The best time to raise this is during the transition itself, while your continued cooperation still has real value to whoever's asking for it, rather than after the fact, when there's less to negotiate with.