Can't be sure, but I suspect the "party" in question is Western Investments, the second largest holder of NRO (and NRI), after Deutchebank. Western and its affiliates has been systematically selling both NRO and NRI since at least early Nov. I give here the approximate numbers of sell transactions, for NRO only:
From Nov. 1 thru Nov. 19: 71,000
From Dec. 31 thru Jan. 10: 465,000
From Jan. 25 thru Feb. 14: 429,000
That's well over 900,000 shares total, and there might have been more sales.
This info comes from SEC filings, which can be found on the NRO sights in ETF Connect.
Would appreciate any interpretation of these sales from any poster.