Here's Glassnode's chart of new addresses. The red line is the 30D moving average.

Whoever is buying right now is either 1. keeping their coins with the exchange (not creating new addresses) or 2. keeping large numbers of coins per address (not a small buyer).

So if the small retailers are buying en masse, they are doing so on exchanges and via ETFs and not holding self-custody.

It's really hard to find out how many individuals hold their BTC on an exchange...this Bitcoin.com news article about a shitcoin wallet claims that "researchers from the University of Illinois report that self-custody wallets now hold over 35% of total crypto supply, compared to 25% in 2022." It doesn't have any citations...but maybe this implies like 65% of retail investors choose to use exchanges?

There's this MarketWatch report (citing a Nydig report form december 2024) that says "Retail investors were the largest owners of bitcoin ETFs, accounting for $77.9 billion, or 74% of the asset under management by such products as of Dec. 31, 2024"

As far as big buyers:

This Coinshares report says that corporate holdings of BTC have increased 18.76% YTD. The report also notes that "institutional investors retain a 22.9% share of total US Bitcoin ETF AUM."