On the economic effects of the text completion interface: empirical analysis of financial markets

In financial markets, investment options are relatively fixed but may occasionally change as new securities (tickers) are introduced to the markets. Theory on exploratory behavior suggests that when new tickers are introduced, the text completion decision aid (autocomplete) can facilitate diversion of market participants from their initially intended ticker to the newly introduced ticker. We analyze whether such diversions have an economic impact in terms of transaction loss. Consistent with our hypothesis, we provide evidence that upon ticker introduction, turnover of securities that are syntactically similar to a newly introduced security is significantly reduced by 3%–5% around the starting day of trade of the new security. Autocomplete appears to have a significant economic effect on market transactions.