How risky is USDT?

I've heard a lot about cryptocurrencies lately, and USDT has caught my eye. But I'm a bit concerned about the risks involved. Could you please explain to me how risky USDT really is? I understand that it's a stablecoin pegged to the US dollar, but I've also heard about some issues with its backing and liquidity. What are the potential risks I should be aware of if I decide to invest in USDT? And how can I mitigate those risks?