I posted about this a week or so ago. Someone could come steal all of our "secret source" and still have absolutely no advantage over us. If the value of your business is entirely in the source code, you need to seriously re-investigate what exactly it is that you are doing. AAA gaming and Windows codebases have been leaked. In some cases partially, in others comprehensively. At no point do I recall Valve or Microsoft seeing adverse competition or other meaningful impact from this event. Legal teams were certainly up in arms, but in terms that investors would care about nothing really happens.
Turns out, you need more than source code to run a business. You need customers, markets & relationships. You need trust. You need a sales team. That's the real thing you should be worried about being stolen. Your goddamn sales team. Obviously the developers would be worried about the code base (and they should be) but at scale it's not the end of the world if some code gets out. Losing your best sales person & all their prospects would be much more catastrophic for your business.