The medical supplies manufacturer, based on Sublette Avenue, is one of St. Louis鈥� smallest and quietest public companies. Run by a board with an average age of 75, it rarely makes news and hasn鈥檛 turned a profit since 2011.

Still, Allied provided thrills and spills this week for folks who get an adrenaline rush from day-trading obscure stocks. The St. Louis company鈥檚 shares nearly tripled in value in a two-day span, then fell by almost half in the next two days, before rising 28% on Thursday.

As of Wednesday, even after that roller-coaster ride, Allied shares had more than doubled in the past month. The from the company was the appointment of a new director Dec. 27.

According to , some traders think Allied, which makes ventilators and other respiratory products, might benefit from the outbreak of a new strain of coronavirus in China.

A Twitter account called put Allied 鈥渙n major watch鈥� Sunday night, after the shares had nearly doubled last Friday. 鈥淐an see a short term upside momentum driven by virus scare and this company happens to have respiratory supplies,鈥� its alert said.

The website 24/7 Wall Street on Monday among 鈥�12 stocks surging that could help treat or fight coronavirus.鈥� By Tuesday, the stock started falling.

Allied itself hasn鈥檛 said anything about coronavirus. Company officials didn鈥檛 return calls asking for comment on the trading activity.

Trading volume in Allied surged to 4.6 million shares last Friday and 4.5 million Monday, which is a lot for a company with just 4 million shares outstanding. Before the frenzy began, an average day saw just 22,000 shares change hands.

There鈥檚 nothing rational about this trading, of course, but speculation can create its own momentum. Day traders don鈥檛 care whether coronavirus really helps Allied鈥檚 business, they only care what the stock chart looks like.

Juli Niemann, an analyst at Smith Moore & Co. in Clayton, sees no sign of smart institutional money moving into Allied, just a lot of people making relatively small trades. 鈥淚t really is a sucker鈥檚 game being conducted here,鈥� she says.

For every about making $1,500 trading Allied on the way up, there鈥檚 undoubtedly somebody who lost $1,500 on the way down.

In fact, the losers probably outnumber the gainers because microcap stocks are expensive to trade. The bid-ask spread, a measure of trading costs, was nearly 8% for Allied on Wednesday, compared with 0.006% on technology giant Microsoft.

Microsoft is followed by every firm on Wall Street, but tiny companies are ignored by analysts. 鈥淭he less information you have, the less efficient the market is, and this is a case in point,鈥� Niemann says. 鈥淭he rumor mill is not an efficient market.鈥�

The rumor mill has picked up on Allied before. When Ebola was devastating Africa in 2014, Twitter users pointed to Allied as a possible beneficiary. The stock was extremely volatile, at one point jumping 78% in a single day.

As it turned out, Allied鈥檚 sales fell 2% that year and its made no mention of any gains from Ebola.

It鈥檚 still possible that Chinese authorities will need a lot of Allied鈥檚 鈥渕ass casualty ventilation products,鈥� a business line mentioned by some speculators on Twitter. More likely, though, the day traders will soon move on to some other quarry and Allied shares will return to their slumber.