Longfin Corp. took advantage of post-financial-crisis rules designed to create jobs and help young companies go public. But the financial-technology company, which was valued at $5.4 billion as recently as 10 days ago, is now under investigation by the Securities and Exchange Commission after it failed to disclose important information and left a trail of misstatements behind.

Since Longfin’s December initial public offering, which raised $5.7 million, the company’s price first rose 13-fold, then fell by 80%, all in less than four months. In the run-up to the IPO, the company, which says it operates computer platforms for trading on the Singapore and other stock exchanges, failed to disclose important information and misstated facts as basic as the age of its controlling shareholder, according to a review of securities filings.

On Monday, the company disclosed the SEC probe while also reporting material weaknesses in financial controls. The company, which said it is cooperating with the probe, said it may not be able to continue as a going concern.

The shares closed Monday down 17% at $14.31, above its IPO price of $5.

Longfin went public using a provision of the Jumpstart Our Business Startups Act of 2012, known as Reg A+. The rules allow companies with less than $1 billion in annual sales to bypass some accounting and disclosure requirements imposed on bigger companies, but they do require accurate reporting.