Trading ETFs, Liquidity, Depth Are Different
While I've often focused on liquidity as a measure of ETF health, a quick glance at average daily trading volume is not enough to prevent purchases at a premium and disappointing sales at discount.
The new long-term oriented ETFs, such as the First Trust Multi-Asset Dividend Income Index ETF(MDIV) , provide a good snapshot of how apparent liquidity and surprisingly high volatility can coexist.
Launched earlier this month, MDIV's average daily trading volume, 70,000 shares, is relatively robust for a new fund, the type of statistic that generally suggests a level of relative trading ease for the average investor looking to allocate a portion of their long term portfolio to the fund.
An ETF is relatively easy to trade when investors can enter and exit the ETF (buy and sell shares) at a price close to underlying value or NAV. Generally, the presence of competitive buyers and sellers, often reflected by high average daily trading volume, help to keep the trading of an ETF in-line with NAV through the processes of creation, redemption and arbitrage. Competitive buyers and sellers help to keep the promise of the ETF industry: less expensive products sold in real-time trading.
When an average investor has to pay a significant premium to purchase exposure to an ETF (a price higher than underlying value), this promise is broken. The same investor is doubly betrayed if, when looking to sell shares of the same ETF, they find they must sell the majority of those shares at a deep discount.
This story might sound familiar to some ETF investors who have perused a list of recent executions with a feeling of disappointment. It must have certainly felt frustrating for investors trading MDIV last Friday as shares of this seemingly liquid ETF began to diverge noticeably from NAV on low volume trading. After opening at a small premium, it took just 700 shares to dislodge MDIV from underlying value.
In an electronic trading age where bid/ask spreads seem tighter than ever, how can a relatively small buy order in a seemingly liquid ETF produce such a noticeable premium? There's more to liquidity than average daily trading volume and tight bid/ask spreads.