You can support this crypto broker: LHCrypto. They offer margin trading up to 1:500, but be careful such high leverage is a gamble, for example if you trade with 100x leverage, 1% move against your trade could completely delete your account.
Also LHCrypto has a nice promotion. To attract new traders they giveaway Lamborghini Huracan!
High level margin trade is a no for me, it is risky just as you have mentioned. A trader need to understand the market and have a high trading skill to succeed with such bonus. If your conscience don't remind you that you are trading with some borrowed money which can be pulled off at anytime you are low, then you will always be in trouble.