By mapping the blockchains of Bitcoin and Tether, we are able to establish that entities associated with the Bitfinex exchange use Tether to purchase Bitcoin when prices are falling. Such price supporting activities are successful, as Bitcoin prices rise following the periods of intervention. These effects are present only after negative returns and periods following the printing of Tether. Indeed, even less than 1% of extreme exchange of tether for Bitcoin has substantial aggregate price effects. The buying of Bitcoin with Tether also occurs more aggressively right below salient round-number price thresholds where the price support might be most effective. Negative EOM price pressure on Bitcoin only in months with large Tether issuance indicates a month-end need for dollar reserves related to Tether. Proxies for Tether demand receive little support in the data, but our results are consistent with the supply-driven manipulation hypothesis.
Overall, our findings provide substantial support for the view that price manipulation may be behind substantial distortive effects in cryptocurrencies. These findings suggest that external capital market surveillance and monitoring may be necessary to obtain a market that is truly free. More generally, our findings support the historical narrative that dubious activities are not just a by-product of price appreciation, but can substantially contribute to price distortions and capital misallocation.