If its reliability is confirmed in future trials, the test would allow doctors to diagnose the condition earlier and start therapies sooner, before nervous system damage worsens, the researchers said. Pot firms surge as US move to ease curbs sparks hopes of legalization Shares of marijuana companies jumped as much as 37% in morning trading on Thursday after a U.S. health agency’s proposal to reclassify it as a lower-risk substance boosted expectations of legalization at the federal level.