How is JP Morgan commemorated after his passing?

JP Morgan is commemorated with the closing of the New York Stock Exchange (NYSE) following his passing, which is significant because this honor is typically reserved for the deaths of U.S. presidents and other highly esteemed figures. This closure serves as a mark of respect for his substantial contributions to the American financial system and industry. Morgan was instrumental in facilitating the growth of many industries during the late 19th and early 20th centuries, and his influence in banking and finance was profound. Closing the exchange was a way to acknowledge his impact and legacy in American history.

The other options don't hold the same level of significance or tradition associated with prominent figures in history. For instance, while the stock market operating as a tribute could be seen as an honor, it does not compare to the closure of the NYSE. Buying out all his companies or declaring a public holiday would not reflect the same depth of respect shown through the stock market closure and are not customary practices in commemorating someone of his stature.