iRhythm Technologies Sees Surge in Short Interest

Short positions on the cardiac monitoring device company grew nearly 20% in January

Feb. 3, 2026 at 11:31pm by Ben Kaplan

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iRhythm Technologies (NASDAQ:IRTC), a medical technology company that develops wearable cardiac monitoring devices, saw a significant increase in short interest during the month of January. As of January 15th, short interest totaled 2,750,064 shares, a 19.6% jump from the 2,299,440 shares reported at the end of December. Currently, 8.6% of iRhythm's outstanding shares are sold short.

Why it matters

The rise in short interest suggests that some investors are betting against iRhythm's stock performance, potentially signaling concerns about the company's outlook or valuation. Short selling activity can influence a stock's price movements and volatility, making it an important metric to monitor for investors tracking the company.

The details

According to the report, the increase in short interest was based on an average daily trading volume of 818,207 shares, resulting in a short interest ratio of 3.4 days. This means it would take short sellers 3.4 days to cover their positions at the current average daily volume.

  • As of January 15th, 2026, short interest totaled 2,750,064 shares.
  • This represents a 19.6% increase from the 2,299,440 shares reported as of December 31st, 2025.

The players

iRhythm Technologies

A medical technology company that develops wearable cardiac monitoring devices and associated data analytics services.

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The takeaway

The surge in short interest on iRhythm Technologies' stock suggests some investors are taking a bearish stance on the company, potentially due to concerns about its outlook or valuation. This activity is worth monitoring as it can influence the stock's price movements and volatility going forward.