European stocks are heading for their worst day in four years

European stocks are getting ripped to pieces on Monday, and they're on track for their worst day since 2011, according to Bloomberg.

The Euro Stoxx 600 index, which picks 600 of biggest stocks in the eurozone, is down by as much as 5.3%. Things were looking incredibly shaky last week, but today's tumble seems to have been set off by the sudden crash in Chinese equities.

Other Asian markets felt the heat and US futures are looking bad too - it's messy out there.

Here's how it looks:

Business Insider, Investing.com

It's down by more than 15% since a recent high in April - enough for a technical correction (usually considered to be a 10% drop) but not a bear market (usually considered to be a 20% drop).