I am for a medium risk profile and I've already started diversifying. A lot of major "global" or "index" tracking funds are now majority comprised of holdings in Nvidia, Microsoft, Meta, Alphabet and also Tesla. I've seen many supposedly non-tech funds where about 50-75% of their portfolio are linked to this bubble. Sometimes the holdings aren't clear if the fund invests in other funds. As an individual investor I won't be able to react fast enough to a crash, so am being proactive with moving investments so that no more than half is exposed. Will obviously keep an eye on things to reduce that if it looks wise.