Although I do not have exact statistics, I am sure that retail investors continue to buy Bitcoin. Another thing is that not all people on planet Earth have realized the fundamental value of Bitcoin.
Meanwhile, the modern financial system is currently undergoing a transformation. Some countries are forcing the creation of central bank digital currencies (CBDC), while other countries are giving the green light to centralized stablecoins (which are very similar in their properties to CBDC). In other words, a digital concentration camp is being built all over the world, censorship is being introduced, financial and information flows are being controlled.
In these conditions, Bitcoin is acquiring the role of financial instruments of freedom and independence of people. And every person who realizes this is now buying Bitcoin.
Therefore, I am sure that the number of retail investors has not decreased, but of course, such institutional investors as Michael Saylor are more loud, pompous and noticeable.
I think retail investors have taken a break from Bitcoin, especially when the global economy continues to deteriorate. Most people these days are living paycheck to paycheck, and cannot afford to buy BTC or any other crypto (or at least risk their money in crypto, hoping they won't lose it all during periods of high volatility). That, and also the fact that most of the attention is on speculative cryptocurrencies (eg: "meme" coins) instead of utilitarian ones. It's what's driving away retail investors these days.
Rest assured, things will settle after quite some time. Patience is needed during these uncertain times. I'm sure BTC and other cryptocurrencies will turn extremely-bullish soon. Right now, institutional investors are buying all of the BTC. So we should expect altcoin market prices to stall for a short period of time. Just buy, "hodl", and forget about the rest.
