In a letter published last night, Bitcoin Core developer Bryan Bishop, former Morgan Stanley managing director Caitlin Long, e-commerce coding pioneer Chris Allen, founder of Ernst & Young’s blockchain team Angus Champion de Crespigny, and fund manager attorney Gavin Fearey warned the SEC against certain types of new blockchain products. Specifically, the letter focuses on practices employed by New York Stock Exchange (NYSE) owner ICE. At the center of the concern is the practice of pooling assets instead of segregating them by owner, a process know as commingling, and rehypothecation, which allows organizations to claim an asset on its balance sheet while lending it to another party. These practices could lead to a sitution where there is more 'liquid' supply of an asset than what is actually held in accounts.