Take a look at what's been happening in US Treasuries. Yields have been dropping for the last 40 years. Investors have still been happy with their returns because they make up for low yields with increasing prices on those bonds (bond prices and yields are inversely relational).
But, now that US treasury prices have reached their peak (yields can not possibly go lower), it's game over for US treasuries. this is playing out in other bond markets as well too. So, everyone is dumping bonds: see article "Why would anyone hold bonds?", it was shared on hacker news a few weeks ago.
Listen to just about any financial professional speak about bonds: they wouldn't "touch it with a 10' pole", is what you hear more often than not. Especially in the inflationary environment we're in now. Governments everywhere across the globe are up to their eyeballs in debt. the only way out is inflation - they've all realized this. you can't raise taxes, you cant decrease spending. you can only inflate your way out of the debt.
so, basically 100T worth of bonds, a very significant percentage of global assets, is being sold off. And it can't go into cash. So where's it going? Well, equities for the most part, hence the relentless rise of equity markets. but also, other places too like bitcoin because people need some diversification, which used to be served by bonds. In the past, investors recommended 60/40 equity bonds mix. in the future, maybe it's 60/40 equity/commodities/crypto.
I find it very intriguing that this could be the driver, but what do you base that on?