It is distinct from a realized gain, which is locked in by selling. Because the entry is erased when prices retreat, a large paper gain does not by itself mean more spendable money. For an investor as large as a pension fund, turning a paper gain into cash means putting size into the market, and that act itself pushes prices down.
Awaiting gradingThe S&P 500's Record 15.7% Margin Drops to 14.4% Without AlphabetCheck after Microsoft, Meta, Amazon and Apple report Q2 results whether their margins improved similarly, that determines whether 15.7% reflects a broad AI boom or an Alphabet-sized illusion.