In that case, if there is a slowdown affecting the IEOs, then it should be having a negative impact on Binance as well. So far they are doing good, raking in huge revenues from all over the world (especially from East Asia). But it is important to make sure that their revenue model is sustainable. I don't know what percentage of their revenue comes from the IEO listings, but they should be prepared for any adverse conditions affecting that sector.
Another risk comes from the hackers. So far Binance have managed to prevent the hackers from stealing its coins (with the exception of one incident earlier this year, when the criminals managed to steal BTC7,000). The trick here is to stay one step ahead of the hackers. At least half a dozen exchanges including Binance and Bithumb were targeted this year.