PurposeWhile monetary autonomy is self-explanatory for cryptocurrencies such as Bitcoin with predetermined supply path, it is of great interest to probe into the monetary structures of Stablecoins. In these supply contracts and expands and capital restrictions apply due to the existence of reserves as the exchange rate arrangement adheres to a price rule.Design/methodology/approachEver since the launch of Bitcoin and its offspring, examination of cryptocurrencies' trading activity from the empirical finance viewpoint has received much attention and continues to do so. The particular monetary arrangements found in Stable cryptocurrencies (colloquially referred to as Stablecoins), however, have not been properly (1) classified and (2) studied within an empirical international finance and banking context. This paper provides an empirical framework analogous to Impossible Trinity for exploring monetary arrangements across Stablecoins wherein reserves are held as price stability is targeted.FindingsThe study findings of existence of the degree of achievement along the three dimensions of the Impossible Trinity hypothesis, namely monetary independence, exchange rate stability and financial openness for a representative sample able to cover all varieties of Stablecoins, provide fresh empirical insights and arguments to this growing literature with respect to the success of their embedded exchange rate stabilization mechanisms. While the hypothesis can be supported for all cryptocurrencies in question, the trade-off combination among exchange rate stability, capital openness and monetary independence varies with the categorical types of Stablecoins.Research limitations/implicationsIf Stable cryptocurrencies, therefore, claim the role of global monetary assets freed from sovereign limits and national boundaries, it is critical to explore whether they adhere to traditional monetary frameworks. It goes without saying that in this work the author does not use a complete catalogue of all the available Stablecoins, rather a complete catalogue of all the possible asset classes of Stablecoins. While there is a significant difficulty in finding Algorithmic Stablecoins and, so far, there is plethora of Stable Token initiatives, a broader sample to further examine these under this paper's empirical framework is suggested. Enrichment of the robustness analysis by constructing additional proxies, possibly building time series for the proposed cmo1 subindex and using additional estimation methods is encouraged.Practical implicationsStablecoins have been developed aiming to address the issue of excessive price variation in cryptocurrencies such as Bitcoin. Holders of Stablecoins enjoy the combined advantages of using a blockchain-based digital infrastructure in fulfilling the functions of store of value and media of exchange and of using a traditional currency, which merely plays the role of the unit of account (and in some circumstances the trusted reserve to which is convertible to). Understanding the varieties of Stablecoins and quantifying the components for success of their price stabilization may result in designing better Stablecoins.Social implicationsBlockchain and cryptocurrencies have introduced new challenges to money and banking. Cryptocurrencies, which independently float such as Bitcoin, have gained the interest so far due to price variation that allows for gains. But these should be by far not considered to be a substitute to traditional means of payment. Lately, Stablecoins have increasingly gained attention for that USD Tether/Bitcoin pair (a Stablecoin pegged to the US dollar at parity) has outrun the US dollar/Bitcoin pair as the most traded pair in digital exchanges marking the strong position and high demand for Stablecoins.Originality/valueThis approach uncovers the varieties of Stablecoins with respect to their monetary constraints compared to the rest of the cryptocurrencies, which independently float. In this paper, the author provides a conceptual framework for the analysis of the exchange rate mechanisms conditional on Stablecoin asset classes accompanied with an empirical study from the monetary viewpoint. This is the first work in this attempt. The empirical framework employed is analogous to the traditional theory of international monetary economics referred to as Impossible Trinityz.Peer reviewThe peer review history for this article is available at: https://publons.com/publon/10.1108/JES-06-2020-0279