I don't think this is entirely correct, and steve might be more right.
The market started tanking when the COVID19 hit China, they quarantined, and then came the fears about supply chain disruptions. It was a fear demand would outweigh supply. It rebounded a bit last week when China's numbers started to flatline and factories came back online.
It started going down again last Thursday and Friday as the outbreak hit the US, cancellations and quarantines started happening here, and Italy shutdown half of its country Friday. This shifted the fears to a demand slowdown, which led to fears of a recession. This is also why oil had already dipped to the high $30s/low $40s. Then Russia and Saudi Arabia pulled their stunt over the weekend.
The market declined started as a demand/supply chain panic and turned into fears over demand/recession. Yes, oil didn't help. But keep in mind, even with the sell-off, we still haven't seen the impact of lower corporate earnings and weaker economic data. If this virus spread continues at the pace it is on and earnings and GDP take a hit, we could go lower.
If it was the OPEC issue as the contributing factor, we would not have seen the rally we did today based on maybe the administration going to eliminate payroll taxes or a package to pay for time off work. That has nothing to do with oil.
Yes, we will adjust and market history shows we recover from every unforeseen event. But the average time of recovery is at minimum 100 days after the event, and we may not be done yet with this "event"
