Yes, but investors move in and out of cash positions. Bershire Hathaway is currently sitting on $334 billion in cash. If you're an active investor, you'll have periods of both buying and selling - so you'll have cash, or you won't have cash. To assume 100% is allocated at all times is incorrect.
Investors do hold some cash, but they generally prefer not to hold a lot of it because inflation reduces its value. $44B sounds like a lot of money, and it is, but it’s only around 8% of the $632B of assets they hold. (Not sure where you got your much bigger figure; mine is from their consolidated balance sheet reported in their 10-K report for Dec 31, 2024.)
