Bitcoin is back under pressure with a $1200 fall in the past few hours. The selling has accelerated in the past few minutes, hitting $40,769.

The weekend low was $40,516 and that will be the key support level today, along with $40,000.

If that breaks, a run on stops could cascade but there would be some hope that the September low of $39,569 could hold.

This is very much a head-and-shoulders top:

Bitcoin chart

In terms of weekend news, there's an interesting feud brewing between CoinDesk and Tether as the news operation tries to get access to disclosures on reserves made to New York regulators in a freedom of information request. That prompted a backlash from Tether but it's only adding to worries/conspiracies about the $71 billion backing of the stablecoin.

In the broader market today, the winds of risk aversion are blowing and that doesn't bode well for tech or crypto, which have largely traded in tandem so far this year. Nasdaq futures are down 1.1%.