This article by now 82-year old investing giant Jeremy Grantham nails it. Well worth the read.
As for the canaries in the coal mine, a good one to follow would be in my back yard – Ballard Power (TSX: BLDP), a perennial cash burner that is currently cashing in on the Hydrogen rush. Notably since 2004 they have not made any cash through operations, and have not made any net income aside from 2008 when they had a one-time gain (my memory faintly recalls a one-time sale of tax loss credits!). Doesn’t mean they won’t be making money in the future, especially from federal government subsidies for our bold hydrogen energy economy!
A hint for Ballard executives (after you’ve cashed in stock options): Do a secondary offering.