Berkshire's market price return has been essentially market tracking over quite long periods, but in particular almost all of the last 2.8 years.

The last 10 years actually.

The link/plot indicates data from Jan.2,2004 to Jan.7,2025 - so 21 years?

I have a question for the group. Why has the mix of businesses in BRK tracked the different mix of businesses in the SPY so well for so long?

Berkshire is dominated by insurance, BNSF, BHE, the stock portfolio, a mix of businesses (MSR)that generally mirror the US economy, and a surprisingly constant percent of cash until very recently. Not a particularly fast growth mix. The S&P 500 carries no cash and has been dominated in recent years by the "Mag 7" type businesses that are fast growing,now very large,and throw off lots of cash - the balance being businesses that make up the US economy. Except for Apple, BRK hasn't participated in the Mag 7 unless you balance the BYD investment against Tesla. These appear to be different mixes - yet the market values them the same. Why?

I no longer follow the details of BRK in the depth I did in earlier years. Nor do I still keep the detailed records I once did. I no longer need them to make simple Buy, Sell, or Hold decisions. So I can't offer any particular insights re the foregoing. I do note that BRK tends to zig when the market zags except in market crashes when everything is correlated. There must be counter-balancing factors between BRK and the SPY that tend to even out the results over time. But I don't have data.

BRK seems a lot safer than the SPY. So the higher risk SPY should deliver higher rewards over two decades shouldn't it? Yet BRK keeps up.

Any thoughts appreciated.