No this is not an article about a liquidity mismatch between ETFs and their underlying products, well at east not entirely. The FT has published a new article by an asset management industry insider arguing that to understand the implications of passive investing, one needs to look more broadly than ETFs themselves. In particular, the piece contends that it is the rise of algorithmic trading which is the true danger, as the technologies which now dominate market trading are agnostic of human-based warnings and insights, and instead simply trade on momentum. This means there are and will be dangerous run-ups and losses in shares. The article points out that only 10% of equity trading now occurs from traditional discretionary human traders. Overall, the piece warns that the current market structure runs very large risks of volatility getting out of hand, and ETFs being forced to dump way more shares than the market can absorb, compounding losses.
FINSUM: This argument is what we would refer to as a “snowball” risk, as it basically discusses the multiple levels of knock-on effects from an initial jump in volatility, which would then be followed by algorithmic selling, then ETF selling, and the cycle continues.