Nortel. Blackberry. Barrick Gold. And now, Valeant.

When a non-bank becomes the biggest company on the TSX, beware.

Read: Turning deeper understanding into higher returns

Maclean’s economics writer Jason Kirby points out that since 2000, seven non-bank companies have become the biggest company in Canada by market cap, and all have since tumbled from that lofty height.

Combined, the companies’ declines have erased $655 billion from shareholders’ ledgers, Kirby calculates.

The biggest collapse is still Nortel, which took out more than $300 billion in value by the time it declared bankruptcy in 2009. But as of early April, Valeant was in second, having declined $100 million since its peak last summer. That includes a rough day in March 2016 when the stock dropped 49%.

For the full list, and what these companies’ troubles say about the Canadian market, read the full article at Maclean’s.

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