This was a 'liquidity carpet bombing' targeting all the large/small equities of the S&P500.
XLK attracted money, but such traditional sectors as health or housing also attracted money.
We can see below that both the NQ8 and the ARKK ETF were weaker in terms of price, but they still attracted some of the money that was made available. This tells us that the market move was not a speculative move targeting either the largest or the momentum stocks. It was very broad... as if there had been a sudden switch in regards to markets value perception.
Value is best measured by comparing the yields of different instruments. Hence, when the S&P500 pushes close to its most recent highs on a strong flow of money, we might suspect that equities are becoming more attractive compared to Treasuries.
But we can see below that the 10Y Treasuries Yield was increasing on Friday. Hence, in terms of valuation, equities should have dropped on Friday.
The 10Y Yield at 1.62% imply a S&P500 price of about $3700. The fact that we closed higher might imply that investors (large funds probably) believe that the 10Y yields are going to drop back down to 1.5%. This would push equities even above $4000 in a momentum move that will reinforce the yields drop. Eventually, this would fail because of inflation fears.
But 10Y buyers are rather eager, which means that they do expect lower rates.
On the other hand, gold and cryptos should be doing well in a lower rate environment. We do not see such an expectation here, but these markets are relatively tiny compared to the 10Ys.
By the way, the velocity of money is extremely low, indicating that the liquidity made available is not helping the economy. Most of the liquidity is indeed captured by the banks' Excess Reserves that are stored at the Fed against a small fee - that in fact becomes a main part of the banks income just due to the size of the liquidity.
Conclusions:
The sudden jump of the S&P500 indicates that investors are expecting a large drop in the 10Y Yields. This drop could come through increased QE - to be announced - or through renewed foreign bond buyers at the start of Q2.
