Zulutrade is scam, like absolutely any system that pays off with a markup on the spread.
Mql5 signal holds the road at the technical level, which is not surprising since it is implemented natively in the platform.
The big problem is mostly customer requirements in terms of return. The second problem is that 98% of signals are based on grid trading with martingales more or less concealed.
But when a signal seems interesting, the audience is impressive. The signal 'Calm' based on a penny account with a starting capital of $ 100 .-- has more than AUM 8 million.