The on-chain activity for the three of the biggest stablecoins exploded as Bitcoin (BTC) was breaking the $11,000 price barrier.
7-day average transfer volume for USDT, DAI, USDC & BTC Price
7-day average transfer volume for USDT, DAI, USDC & BTC Price. Source: Glassnode.

Stablecoin growth

Several stablecoins, including the market-leading Tether (USDT), have recently experienced a significant growth in market capitalization. We observe that a significant increase in the transfer volume of USDT, DAI (DAI), and USDC (USDC) coincided with the latest Bitcoin bull run. It is not clear from the chart whether this metric can be considered a leading or lagging indicator.
The increase in stablecoin transfer volume, unlike the increase in trading volume, is a better representation of the coin’s utilization within the crypto ecosystem. Although no real bull run can happen without the injection of additional fiat, when it comes to Bitcoin trading, stablecoins seem to prevail. It appears that most whale trades are transacted with stablecoins, not with fiat.

Tether $300M swap

Earlier today, Tether announced a 300 million USDT swap from TRON (TRX) to Ethereum:
Twitter
Source: Twitter.
The company did not provide rationale for the swap, but it is possible that there is a lack of demand on the TRON network.