I think the reason why he is so cautious is because, as he said, the range of outcomes in the pandemic is so wide.
He has lived through many recessions in his live and despite the differences they all have many things in common and I am sure He has developed a mental model to apply to recessions so He is comfortable buying stocks during those times.
This case is different, this situation is new for all of us, nobody has any experience living through this and nobody know what the consequences will be.
The way he has built his wealth and Berkshire is betting on companies that will do well but most importantly that have no risk, in his mind, to become worthless.
He has repeatedly said he would never invest in a share that could be a 10 bagger if there is any small chance that it could be a zero.
That is why he doesn't invest in technology, before he invests in a company he has to visualize and become comfortable with how the company would look in 5 or 10 years and that is very difficult to do with technology companies.
What is the upside of going all in in the march low? A few extra points of performance for the next few years?
What was the downside if the pandemic was worse or if the Fed wouldn't have acted the way it did?
Even now though the range of outcomes is narrowing, still there are lots of unknowns. And spend your cash doesn't seem to me like the best idea.
What if the vaccines don't work, what if the government reduce the stimulus?
Both are unlikely but there isn't a zero chance of them
On the other hand I find ridiculous all the bashing of Buffett and Berkshire over the recent months because of the underperformance.
Has Berkshire underperformed the S&P 500, not to talk about the Nasdaq over the last 5 and 10 years by a good margin? Obviously yes but consider this.
At the top of the last cycle (December of 2007) Berkshire book value was 78000 per A share at the end of December 2019 it was 262000, more than tripled over 12 years.
How is that a bad outcome?
We can also compare what their cash, securities, earnings power was then and now and in my opinion Berkshire has done an excellent job in the last decade at growing intrinsic value taking very few risks.
By the way the share price has gone from150000 at the end of 07 to 337000 at the end of 2019. So the multiple for Berkshire is lower while the multiple of the market as a whole has gone up substantially hence the underperformance.
Going forward I think they will outperform the index, not because they will have crazy returns but because I think it is hard to see the market going up 8% a year in the next decade while it is easier to see that kind of compounding from Berkshire.
The only things that bothers me a little about the way the company is managed is that I don't think they will do substantial buybacks while Buffett is managing it (I hope I am wrong). I think he is a collector of businesses and I don't think he wants to erode his capital base in any substantial manner so that he can acquire big companies when the opportunity arises. I think he would love for Berkshire to be the biggest company in the world and that could blind him and reduce the buybacks even when they would make sense