Vanguard auto realized gains at the end of the year on VWUSX

Hi, PF.

Basically the title.

Noticed extra cash in my Vanguard brokerage – was initially suspicious. After looking at the transaction history it looks like Vanguard realized my gain on VWUSX holdings (both short-term and long-term). This happened in both IRA and regular brokerage account.

Why does this happen? I was not expecting to pay taxes on my gains, or even realize them. Was just going to hold.

Very confused by what’s going on.