Tuesday began in Europe with that sinking feeling.

Major bourses slipping into the red after the open as they too experienced the latest anxiety dogging U.S. markets.

Namely, the imminent possibility, according to sources, of regulatory probes into FAANG giants Amazon, Apple, Facebook and Google.

Time, say some Wall Street watchers, to cash in, perhaps.

After a combined $85 billion was wiped off Facebook and Google parent Alphabet's values in the market slide there.

SOUNDBITE: LADENBURG THALMANN ASSET MANAGEMENT CEO PHILIP BLANCATO (ENGLISH) SAYING: "Suddenly, there's some headwinds around those companies that I think again give you a chance to take some profits.

I'm not saying be out of them because they are still the drivers of the overall economy to a great degree.

But take some profits here." Europe's benchmark STOXX 600, fresh from posting its worst monthly performance in over three years in May, shed half a per cent before recovering.

Tech stocks were down over one a half per cent.

And adding to the new worries were familiar ones: trade.

Recent moves to ratchet up U.S./China tensions still put no end in sight to their tariff tiff.

SOUNDBITE: LADENBURG THALMANN ASSET MANAGEMENT CEO PHILIP BLANCATO (ENGLISH) SAYING: "There's no reason to be risky here when the underpinnings of the economy are softening and there's not a catalyst other than maybe the Fed to drive the market higher unless we got a surprise for second quarter GDP and earnings.

And I just don't see that." Cars and banks held their nerve to post strong gains.

But commodities markets continue to buckle as those worries dig deeper.

Oil prices now 20% per cent beneath this year's peak.

Prices for LNG and thermal coal are at multi-year lows.