These are solid ETFs for sure, but I'm in the same line of thinking as you, they've run up in price significantly, and these types of returns are simply unsustainable.
I see a lot of investors thinking these ETFs are a one stop shop to riches. I mean, those who started investing in 2020 and bought them, I don't blame them for thinking that. ARKK has gone up 225% since the March crash.
Prior to this however, ARKK had a compound annual growth rate of 10.91% the previous 6 years. It gained more in 3 months in 2020 than it did in the previous 6 years.
This ETF has severe concentration risk to companies that have absolutely soared in value over the last while. It's biggest holdings are Tesla, which has increased 707% over the last year, ROKU which has increased 217%, Invitae which has increased 185% and CRISPR Therapeutics which has gone up 265%.
These four companies make up over 32% of this ETF.
You are not unreasonable at all to think this ETF carries considerable risk due to its over exposure to soaring tech and Tesla. If I were forced to place a bet, I'd say we see some consolidation. But again, the stocks that make up the bulk of this ETF have been unreasonably expensive for some time now. Who knows what they'll do in the future.