Bansari Kamdar

(Reuters) – U.S. media company Insignia Systems increased its month-long rally to the last hours of December. This set it up for the most successful month in decades as retail investors bought shares of the micro-cap stock.

As of Wednesday, 0322 GMT, Insignia had increased nearly 20% and was up more than fivefold since December. This is its best month performance since 1991.

Although the company’s share price has risen 130% this week so far, it still falls short of the 319% weekly increase in December when it stated that it was looking at strategic alternatives.

Fintel currently has Insignia at the top of its leaderboard, which tracks companies most likely to experience a short squeeze. S3 Partners is an analytics firm that estimates that Insignia will suffer a short-interest of 63.6% from its free floating.

According to Fidelity Research, the Minneapolis-based company ranks among the most trending on social media Stocktwits.com. It is also the third-most-ordered stock by individual Fidelity Investors.

High short interest stocks have been in the spotlight since individuals investing in online message boards facilitated spectacular rallies in share prices of companies like AMC Entertainment (NYSE) or GameStop(NYSE:). This has cost short sellers billions.

The short interest in Insignia has increased by 543,000 shares during the past 30 days. That’s $6 million worth of value, according to Ihor Dusaniwsky (managing director, predictive analysis, at S3 Partners). Last week, there was 16,000 shares of $182,000.

Dusaniwsky stated, “It must be long buying.” “This is a stock with a small market cap, small float and tiny amount of borrows available – there will be virtually no new short selling in this stock due to lack to stock loan supply.”

According to Refinitiv data, Insignia was worth $40.7 million and had 1.77million shares remaining.