Short interest explained. The squeeze indicator.

Short interest measures how heavily a stock is being bet against by short sellers. The metric flags potential squeeze candidates before the squeeze starts, identifies stocks where bearish sentiment has reached extremes, and warns shorts that their borrowed inventory is becoming hard to find. Reading short interest correctly gives the trader a structural read most retail does not have.

What short interest actually is

Short interest is the total number of shares that have been sold short by all market participants and have not yet been covered. The shares are borrowed from brokers and sold by short sellers who plan to buy them back later (hopefully at a lower price).

FINRA requires brokers to report short interest twice monthly. The reports cover positions as of the 15th of each month and the end of each month. The data is published roughly 2 weeks after each cutoff date.

The settlement delay matters. The reported short interest reflects conditions from 2 weeks ago. The current short interest may be meaningfully different. Real time short interest is not publicly available, though paid services (Ortex, S3 Partners) provide daily estimates based on broker borrow data.

The percentage of float metric

Absolute short interest is less meaningful than short interest as a percentage of float. The float is the number of shares available for public trading (excluding insider holdings and restricted shares).

Short interest of 10 million shares on a stock with 1 billion shares of float is only 1 percent. Not meaningful.

Short interest of 10 million shares on a stock with 30 million shares of float is 33 percent. Very meaningful. The shorts collectively need to buy back nearly a third of the available shares.

The percentage of float metric normalizes the data across different sized companies and produces comparable readings across the universe.

The squeeze thresholds

Above 10 percent of float. Elevated. Worth attention.

Above 20 percent of float. High. The squeeze risk is meaningful if the stock starts rallying.

Above 40 percent of float. Dangerous for shorts. Squeeze territory.

Above 100 percent of float. Extreme. The shares have been lent and re lent multiple times. The shorts collectively cannot all cover without the price moving dramatically. GameStop reached 140 percent of float during the 2021 squeeze setup.

The higher the percentage, the more dangerous the position for shorts and the more likely a squeeze if a catalyst arrives.

The days to cover metric

Days to cover is short interest divided by average daily trading volume. It estimates how many days of normal volume would be required for all shorts to cover.

Short interest of 10 million shares divided by average daily volume of 2 million shares equals 5 days to cover. If all shorts tried to cover simultaneously, it would take 5 days of normal volume.

Below 3 days. Low. Easy to cover quickly.

3 to 5 days. Moderate.

5 to 10 days. Elevated. Cover would take meaningful time.

Above 10 days. High. Squeeze pressure would build rapidly because shorts cannot cover quickly without driving the price up.

Days to cover compounds with high short interest percentage. A stock with 30 percent short interest and 10 days to cover is in different territory than one with 30 percent short interest and 2 days to cover.

The cost to borrow companion metric

Cost to borrow (CTB) is the annualized fee shorts pay daily to maintain their position. Easy to borrow stocks have CTB under 1 percent. Hard to borrow stocks can reach 10 to 100 percent annualized.

Rising CTB signals that the broker inventory is becoming scarce. When CTB rises above 10 percent, the shorts are paying meaningful money to maintain the position. When CTB rises above 20 percent, many shorts cover proactively because the carry cost is unsustainable.

CTB data is available from broker prime services and from paid third party services. Free sources are limited.

What short interest does not tell you

Not the direction of the next move. High short interest signals squeeze potential but does not say when. The squeeze may happen this week, this month, or never.

Not the cause of the short position. High short interest can reflect legitimate fundamental concerns (the stock is overvalued) or coordinated retail attention (the WSB effect). The metric alone does not distinguish.

Not real time. The FINRA data is 2 weeks delayed. Current short interest may be different from reported.

Not perfect. Some short positions can be hidden through derivatives or hedging that does not show in the standard short interest reports. The metric is the best available signal but not complete.

How short interest combines with other metrics

Small float.

High short interest on a small float (under 50 million shares) compounds the squeeze potential. Smaller floats produce more violent moves on the same dollar volume.

Recent technical breakout.

High short interest stocks that break out of technical patterns trigger short covering. The technical breakout combined with the short interest setup is the highest probability squeeze scenario.

Catalyst pending.

Upcoming earnings, FDA decision, activist filing, or other catalyst. High short interest into the catalyst is more dangerous for shorts than high short interest without a catalyst.

Rising CTB.

The metric is more powerful when CTB is also rising. The combination signals that brokers are running out of inventory and shorts are paying more to stay short.

How to track short interest

Fintel.io. Free short interest data and history. Good for retail screening.

ChartExchange.com. Free short interest visualization and tracking.

Nasdaq.com. Official FINRA short interest publication. Updated twice monthly.

Ortex.com. Paid service. Daily estimated short interest based on broker borrow data. More current than FINRA.

S3 Partners. Institutional grade short interest analytics. Expensive but comprehensive.

Build a watchlist of stocks with elevated short interest. Track changes over time. Note which ones develop into squeezes versus which ones decline normally.

The setup for using short interest

Weekly review of stocks with short interest above 20 percent of float and days to cover above 5. Note which ones meet both criteria.

Sub filter by float size. Prefer stocks with float under 100 million shares for higher squeeze probability.

Sub filter by CTB. Stocks with CTB above 10 percent annualized are showing borrow stress.

Watch the chart on the filtered names. The squeeze candidate that also breaks out technically is the entry signal. Without the technical breakout, the high short interest can persist for months without triggering.

Position size small. Squeeze setups carry high tail risk both directions. Sized appropriately, they can produce explosive gains. Sized too large, they can produce account ending losses.

Where the audit fits

The audit is not a squeeze chasing service. It does identify whether the trader has accumulated losing positions from chasing high short interest stocks. For most retail the pattern is buying squeeze candidates after the news, which is too late. The plan installs the rule that squeeze setups require the technical setup PLUS the metrics, not the metrics alone. Five to seven pages.