🚨Have you ever wondered how important token "unlocks" are?  In general you should consider that VC invest in a project in the early stages (funding) and will get tokens at a discount (when it is created). The purchase price is so low that it is very likely that when they will get liquid tokens (after a vesting period) they will have nice multipliers to sell on the market (VC with the unlock of $Tia in October 2024 were doing between 100x and 150x, despite $Tia not being in ATH for a long time).

Why does nothing happen on the unlock day? Simply unlock is priced in the previous months with market sales or short (perps/futures).  
Will VC, having obtained tokens from vesting, sell it? It depends. They are certainly not interested in long term (years) to hold any altcoin they invest in. Some VC may also decide to short token (with a small %) in their vesting months/years.