That's the thing about Hussman. He doesn't come across as a crackpot. He always seems very reasonable and nuanced. He brings up good points. He's just spectacularly bad at investing.

Well, unless you are investing with him, which I don't think any of us are, his investing performance doesn't matter to us.

However, the essence of what he is saying is just simple arithmetic which anyone can easily replicate.

Using latest available May 24 CPI of 314.069:
sp500 real sales at 2000 yearend = 1355
sp500 real sales at 2023 yearend = 1925

This translates to 1.54% real sales growth over 23 years and also is in line with the very long term historical average for real sales growth.

We can now fairly reliably estimate that 10 years from now, at 2033 yearend, real sales will be 2243. Where will the index be? That's tricky because it depends on the profit margin and multiple. Assuming a 10% profit margin and multiple of 18 gives us sp500 at (2243/10)*18 = 4038 real.

Starting from today's all time high close of 5567 and assuming a 2% dividend, which currently is only 1.25%, gives us a real return of -1.16% over the next 10 years. Since inflation will definitely be well above 1.16%, we can expect a positive albeit small nominal return even buying today at 5567. Since it's essentially a zero real return and it won't happen in a straight line, Hussman calls it a long and interesting trip to nowhere. Depending on what the profit margin and multiple actually end up being, the actual return will obviously change accordingly.

Seems to me, buying the index even at today's lofty prices, may still more or less keep up with inflation for a 10 year holding period. Those dollar cost averaging may get a chance to buy at lower prices along the way thus improving returns.