CTB
Cooper Tire & Rubber Co.
stock NYSE

Holding:
**$ONCO** - High Short Interest and CTB, trending through AH, Float under 1MM, Trending through ON
**$GETY** - Trending, Merger with Shutterstock, received conditional approval from UK's Competition and Market Authority (CMA) last week.
**$INO** - Hanta/Ebola

The CTB data on ChartExchange is from **IBKR**. Sometimes it shows up delayed.
Here is another site which tracks the same data: [https://www.iborrowdesk.com/report/GME](https://www.iborrowdesk.com/report/GME)
It's up to date. Here's the data from market close:
https://preview.redd.it/mogzxk2n512h1.png?width=349&format=png&auto=webp&s=9e5698fb1107864687ef1899c8429674ed40a0b9
Note that this is IBKR data only and not a market-wide average. Rates can vary a bit, between brokers.

I noticed this today as well, and it is strange. Important to note though, GME is not the only stock affected. Every stock I’ve checked stopped getting CTB updates on ChartExchange at 4:40 AM EDT on May 16th, same as GME.

Your first instinct should be to question this.  The short interest demand (high) and the CTB (low) don't math if you believe in greed.

I understand the mechanics.
When its this easy to short GME directly (large float, very low CTB,, tons of liquid options to hedge with), there is no reason to do it the roundabout way.

Yup!
The default mode is:
If they want to short GME, they go long XRT.
If they want to long GME, they go short XRT.
The exception to this is under trying situations where SI is super high, CTB is very high, and/or options are unavailable or mispriced.

Ok, have had a chance to review. Decent piece of work! Very empirical.
Two thoughts. First, synthetic shorting like the kind they describe is applied in specific circumstances. Specifically:
* Direct borrow is impossible or punitively expensive
* Options don't exist or are too illiquid
* The target stock represents a meaningful weight in some ETF
* And if possible, they're a large enough player that the basket leg is either already owned or executable cheaply
So, GME in 2021. But not GME in 2026, because GME shares are abundant, as are borrowable shares, and CTB is very low.
Second, they would have done well to talk to actual market participants about when this trade is put on.
Thanks again for sharing!

I was seeing a lot of comments about the CTB on other posts and was curious myself. CAR’s CTB during its squeeze only peaked at 11% and that was post squeeze. I guess with the other mechanics in play (low SF, shares locked up for the most part, plans for buybacks) CTB doesn’t need to be ridiculously high to start the squeeze?
The shares actually circulating in the market are probably low enough that if the price rises and buying pressure increases enough early shorts will scramble to cover which will cause the squeeze to start before CTB can catch up.
From mid September 2025 to now, SI has increased from 35% to 59% while the price went from \~$24 to lows of \~9.50 during the Iran debacle. So 25% of shorts are currently at risk if the price rises past $25 on a thin float of shares, and the remaining 35% are at the risk of whatever price action results from that.
https://preview.redd.it/v6yanauylp1h1.jpeg?width=1170&format=pjpg&auto=webp&s=41e9e67e2a5721dfe4a1028f366a405938472c3e

AUUD - Low float, high short interest, high CTB, and pending merger.
Recent 5 million share offering @ $2.36 is closed. 5 million warrants are still active and can be exercised for $2.36. Total OS after warrants would be 10.5 million. They submitted their S4 for the pending merger on Friday and saw a massive increase in trading volume.