Tether is considered a pioneer of the stablecoin model. As such, it's pegged to an external asset, US dollar, which lets it combine the stability of the real-world investment tools and the earning potential of a cryptocurrency. Looks reliable (if you can call any crypto assets that), which is probably why its share on the market has been growing since its launch way back in 2014. You can see for yourself, just look at the USDT dominance chart we've prepared — it reflects the ratio of Tether market cap to the cumulative market cap of the crypto market.