I don't get it: why can't anyone answer this fundamental question? Isn't this one of the largest forums having to do with stocks?
Well, you did post it on Xmas day, when most were probably otherwise occupied.
But I'll answer it for you.
A SPAC is specially created to be merged with or acquire another company in order to take it public.
It's usually cheaper and more importantly, faster, to do than an IPO.
It's also highly risky for Investors.
The problem is, that often, the SPAC does not specify immediately exactly what company it intends to buy, or even when.
Although the sector (ie 'renewables' or 'materials' is normally specified, like 'Bistro Bars' for instance.
It's a blind investment, very much like writing a blank cheque, initially.
As you wait, meanwhile, the SPAC shares themselves can be traded, which may considerably alter their ultimate value.
Funds are usually held in a Trust or ESCROW account, which offers some safeguards.
In your example, once the target acquisition is known, then;
The hope is, that you will have acquired shares at at or below the launch trading price and can cash out if trading demand then pushes the price upwards. {100%+ gains are not unusual}. Thus you benefit from getting the shares at a fixed pre-market price, although you probably won't know what this will be at the time of buying into the SPAC.
They are also far more accessible to small private retails investors than traditional IPO's, which are rarely available to most retail investors.
As to any shares in the example shell company [ ESC ] being acquired, they will usually be converted directly into shares of the made up new company [ MUNC } at a fixed ratio as specified in the prospectus for the acquisition. You may potentially lose the value of a few shares due to rounding if this is not 1:1. This is not permitted to be significant and will be detailed in the prospectus if applicable.
Effectively, you get an equal value of shares in the new company, at the initial market price at open at least.
I hope this somewhat clarifies for you what can seem like a very complex way of making investments.
MOC.