There is that possibility where Grab's share price could definitely fall below $5, though I believe it is more likely that it will rise.
The company can't afford their share price to fall below $5 as if it is classified as a "penny stock", many investors (especially large funds) will lose confidence in the company and potentially pull out.
Grab shares could go up after March 2022:
Grab is scheduled to announce their first quarterly earnings since going public on 3rd March 2022. If growth/revenue figures beat expectations, there's a very high chance the stock will rebound.
Not to mention Temasek recently bought quite a significant amount of Grab's shares, which I believe is to boost/maintain its current share price (and also to get in low).
Grab still has a long way ahead to go as many of their business units are turning profitable (GrabFood, Ride-Hailing), while their other emerging businesses (Grab Financial, Groceries) have yet to fully take off.
With the pandemic coming to an end and ride-hailing expected to recover, there is tremendous potential for Grab's stock to recover and potentially hit levels of SEA Ltd (Shopee/Garena parent).
In conclusion: I'm still very bullish on Grab.