Investors need to follow best practices when trading ETFs and perhaps the foremost among them is using limit orders, said Joel Dickson, global head of investment research and development at Vanguard. 'Vanguard recommends investors use limit orders, as opposed to market orders and sell stop orders, as a prudent way to safeguard against poor execution in times of market volatility,' said Dickson. Limit orders offer advantages for investors, providing price control and protection, as well as some trading flexibility. Dickson said the significant increase in volume after the market open on August 24th was potentially exacerbated by clients’ sell stop orders, which become market orders, triggered by volatile price action and wider spreads which in turn created even more market orders. Dickson said there is nothing new - or inherently wrong with – so-called smart beta strategies. He said they tend to be overhyped for what they really are, which is market-cap-weighted indexes that have been reweighted to shift risk exposure away from market beta. 'Know what it is. Do the due diligence and then decide if it’s a strategy you want in your portfolio,' said Dickson. When deciding between mutual funds and ETFs Dickson said the most important factors are: investment strategy, trading flexibility, accessibility, and costs.