Yes, that's precisely what happened yesterday. And it was largely done by FINRA reporting entities (likely hedge funds). 30 days of daily data available
here:
I track the reported FINRA short volume daily, then subtract FINRA-reported volume from NASDAQ reported end-of-day volume.
The daily proportion of NASDAQ - FINRA reporting reveals MM daily trading volume, which then permits statistical inference testing on MM daily short selling.
I have just over 14 months of daily data. Validated by the bi-monthly short interest reported by NASDAQ, 'best-fit' curves can be validated and std-error of estimate obtained.
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Note 1: a 'T-score' of -1.52 indicates an event that ranks in the 6th percentile of a normal distribution (ie: you expect this extreme to occur about 6 times in 100 trials).
Note 2: I have 274 data points in my data set. The Jan 6, 2020 t-score of -1.52 ranks #11 out of 274, or 0.040 in the distribution, which should be compared to the population estimate (based on my sample) of the 6th percentile.
@Fact Checking also asked if he was missing something. Yes, it's hidden, but can be teased out of the data.
Note that on Options Expiry Fridays, especially when large numbers of Options expire, we see the opposite shift in the FINRA - NASDAQ metric: a higher proportion of trading is conducted by non-FINRA reporting entities. I'll try to put out another report after this Friday, but be aware that the largest Options Expiry event this month occurs on Jan 17th.