The decision may have been related to insolvency rumors surrounding Prime Trust, a US-based fintech company. On June 8, BitGo announced a non-binding letter of intent to acquire Prime Trust.
After the announcement, the TUSD stablecoin dipped as low as $0.9951. This is a seemingly small deviation from the $1 peg, but in the stablecoin world, such small variances can be serious.