According to the SEC filing on Taikang Life Insurance Company’s 13.5% stake in Sotheby’s stock was acquired over 10 trading days completed yesterday. The firm bought initially in June before filing July 18th. The bulk of the purchases came in a run of buying after the filing.

But the curious thing about the filing is that it says all 7.9m shares Taikang bought were acquired on the open market. Nonetheless, the chart below only shows purchases of 5.2m shares. Did one of the other large holders sell Taikang a 2.7m share stake?