How much StablecoinX stock was sold short in September 2026?

Short sellers held 2,810,986 shares of USDE, the Class A stock of StablecoinX Inc. on Nasdaq, on September 30, 2026. That was the latest settlement date in FINRA's data when this review read it at 22:20 UTC on October 9, the day FINRA published the September 30 figures. The position was 14.7% of the roughly 19.06 million Class A shares that the company's resale prospectus counted as freely tradable on August 28, and 78% more than the 1,579,478 shares held short on September 15.

Short interest is the number of shares sold short and not yet bought back. Member firms report it to FINRA, the self-regulatory body for US broker-dealers, for two settlement dates a month, one in the middle and one at the end. A short sale counts once it has settled, one business day after the trade.

The short position was small next to USDE's trading. In the 11 sessions to September 30 the stock traded an average of 6.96 million shares a day, so short sellers held 0.40 days of volume, a ratio called days to cover. From its first session on June 26 to October 8, USDE traded 380.8 million shares, 20 times its freely tradable shares.

FINRA's daily short sale volume, a separate measure that some websites present as short interest, counts the share volume of trades. Of the 157.0 million USDE shares traded in regular hours and reported to FINRA's trade reporting facilities, the systems that record trades made away from exchanges, 57.8% were marked short. A short sale counts there even if the seller buys the shares back the same day, so the 57.8% measures trading.

USDE closed at $6.12 on September 15, at a peak of $17.25 on September 25 and at $16.08 on September 30. Short sellers as a group held 1,231,508 more shares short on September 30 than on September 15. Short interest is a snapshot at each settlement date, so it does not show when in between positions were opened or closed.

Short interest reached 2.81 million shares on September 30

FINRA collects short positions from its member firms in every exchange-listed and over-the-counter stock under its Rule 4560. Firms report the positions they hold at the middle and the end of each month, and FINRA publishes the totals on the seventh business day after each settlement date. Its short interest data for USDE starts at June 30, the first settlement date after the stock's first session.

This review divides by the prospectus's approximate count of 19,063,653 freely tradable shares on August 28 at every date. From 4 pm on September 14 the resale prospectus also registered for sale the 3,621,132 Class A shares of Ethena OpCo Ltd, an Ethena company, which the prospectus says carry no contractual lock-up. Against those and the freely tradable shares, 22,684,785 in all, the September 30 short interest came to 12.39%. Against the 24,029,375 Class A shares outstanding on August 28 it came to 11.70%. At the $16.08 close it was worth $45.20 million.

The two largest rises came in the second half of August, when short interest grew by 1,035,904 shares as USDE's close rose from $2.93 to $8.87, and in the second half of September, when it grew by 1,231,508 shares as the close rose from $6.12 to $16.08. Short interest in the warrants, USDEW, was 7,731 warrants on September 30, 0.07% of the 11.5 million public warrants.

Short sellers held less than half a day's volume

FINRA listed days to cover as 1 for every date, the value its data shows for anything at or below one day. Divided by the average daily volume in S&P Global's data over each reporting cycle, from the session after one settlement date to the next, USDE's short interest never reached half a day's trading. FINRA's own average daily volume came within 4% of S&P Global's in every cycle but the first. FINRA averages over every trading day in a cycle, and USDE traded on three of the ten in its first.

Trading was heavy for a stock with 19.06 million freely tradable shares. On August 21 alone USDE traded 99.0 million shares, 5.2 times the freely tradable shares, as its close rose 85% from $4.00 to $7.41. That one session lifted the average for the cycle to August 31 to 15.0 million shares a day, which is why days to cover on that date was 0.08. Without it the cycle averaged 6.61 million shares a day, and days to cover would have been 0.19.

Daily short sale volume measures trading

FINRA's daily short sale volume files give, for each stock, the volume of regular-hours trades reported to its trade reporting facilities and the part of it marked short. Trades executed on an exchange are not in them, and exchanges publish their own short sale volume. For USDE the files covered 157.0 million shares over the 73 sessions, 41.2% of the 380.8 million shares in S&P Global's daily volume.

The files count only trades published on the consolidated tape, the public feed of trades, according to a FINRA notice of May 2019. When a firm fills a customer's sale by first selling short from its own account to another firm and then buying the customer's shares at the same price, only the short sale appears in them, which can make the share marked short look high.

Short interest counts the positions open at a settlement date. The daily files count short sales as they trade, including those bought back within hours. In the 11 sessions from August 14 to 28, whose trades settled by August 31, the files counted 41.9 million shares marked short, while short interest rose by 1.04 million. In the ten sessions from August 31 to September 14 they counted 11.6 million, while short interest rose by 347,465. In the 11 sessions from September 15 to 29 they counted 17.5 million, while short interest rose by 1.23 million.

Daily prices suggest the short sale price test covered more than half of USDE's sessions

The SEC's short sale price test, Rule 201, applies once a stock falls 10% or more below the prior day's regular-hours close, for the rest of that day and all of the next, according to the SEC staff's answers on the rule. While it applies, a short sale may not be executed or displayed at or below the national best bid, the highest price any market is bidding, unless it meets one of the rule's exceptions. A firm marks a sale that relies on one short exempt. The listing market decides when the test is triggered, and this review did not read Nasdaq's record of it.

By S&P Global's daily lows, USDE fell 10% or more below its prior close on 25 of its 73 sessions, implying the test would have applied on 39, or 38 if no prior close applied on June 26. Those 39 sessions carried 88.4% of the 6.97 million shares that FINRA's files counted as short exempt, and July 2 alone carried 39.6%. The SEC staff's guidance lets firms mark some sales short exempt on days without the test too, and the other 11.6% came on 25 of the 34 sessions without it.

S&P Global's history for USDE includes a $9.40 close on June 25 on 145 shares, the day before USDE's first session, which appears to be the last close of TLGY Acquisition Corp., the listed blank-check company in StablecoinX's merger that day. A blank-check company is a listed shell formed to merge with a private business. The count uses that close as the prior close for USDE's first session. The SEC staff's guidance says the rule does not apply on the first day of trading of a newly offered security, which has no prior close, and whether Nasdaq treated USDE that way is not known.

What this review could not check

FINRA's figures do not say who held the short positions, why, or what borrowing the shares cost. Some short sales may hedge other positions, such as the warrants, and the data cannot show that.

The September 30 snapshot does not establish the short position at the October 8 close. FINRA published the figures for September 30 on October 9, as its schedule set, and this review read them at 22:20 UTC that day. Each record flags a revision of the figure before it, so a revision of the September 30 figure would show in the record for October 15. None of the seven records read flagged one.

FINRA's daily files leave out trades reported outside regular hours, so the 41.2% ratio is not a measure of all off-exchange trading in USDE. The price test count rests on S&P Global's daily lows. For the 31 sessions from August 26 each was within a cent of the lowest regular-session price in Yahoo Finance's hourly data, and earlier sessions had no second source. Moving any session's low by a cent would add at most one session to the count.

Reproduce the numbers

This review read FINRA's short interest records from its public Query API and its daily files from FINRA's public file server in a browser on October 9, 2026 UTC, with the SHA-256 of each response. The main script checks every input against its recorded hash, that each record's previous position matches the record before it, that FINRA's files hold one USDE row for each session, and that the price test logic marks the day after each trigger. If any check fails, the script stops before writing its tables. Download the short interest table, the daily short sale volume, or the calculation files and source inputs.

share of freely tradable = short interest ÷ 19,063,653 freely tradable shares
                         = 2,810,986 ÷ 19,063,653 = 14.75% on September 30
days to cover            = short interest ÷ average daily volume over the cycle
                         = 2,810,986 ÷ 6,964,553 = 0.40
share marked short       = short volume ÷ volume reported to FINRA
                         = 90,743,186 ÷ 156,995,182 = 57.8%
price test triggered     = daily low ≤ 0.9 × prior close

The StablecoinX dashboard tracks USDE's share price against the ENA treasury the company reports, along with its warrants and options, and its methodology page defines its figures. The September review breaks down what moved USDE that month.

Analysis of public market data. Not investment advice.

Related research: The float and ownership review explains the share-count denominators.