Maintaining focus on an issue is easier when it comes with a snappy, emotive label. Flash orders or dark pools just sound dubious, as does any variant of “naked” trading. The uptick rule, in contrast, suggests a fine, upstanding piece of regulation. Established in 1938, the rule limiting short selling of stocks when their last move was down was abandoned in 2007. However, it is set for a post-crisis comeback. The US Securities and Exchange Commission this week requested additional input on an alternative rule, to allow short selling only above the prevailing best price.

By focusing on prices rather than movement, the rule would, in theory, be simpler to monitor. But the SEC – buffeted by politicians demanding action – has taken an idea and supersized it. Some large stock exchanges in March proposed that such a rule apply only after a stock experienced a precipitous decline, triggered by a so-called circuit breaker. In a fevered atmosphere abusive trading becomes more likely so it makes sense to slam on the brakes. But as a permanent fixture this rule would be an unhelpful drag, restricting short selling's role in greasing the market's wheels and aiding price discovery.

Where other forms of the uptick rule present merely a speed bump to would-be short sellers, the latest proposal is more restrictive. Most probably, exceptions would be required for pure arbitrageurs and market makers, but others who help to keep prices in line would inevitably suffer. Meanwhile, it does little to deter directional short sellers – the real bête noire of chief executives – who are happy to take a position and sit in it for months, if not years. The obsession with short selling is obstructing what should be a comprehensive look at excessive short-run volatility. That, however, is not easily encapsulated in a two-word soundbite.