Graph distribution on Bittrex is for Bittrex accounts ONLY. It shows the higest holding accounts on the exchange, and it has the lowest supply on exchange I have ever seen. Meaning that almost all coins are staking 
If the guy asking above here reffered to the richlist in block explorer. It can be difficult to know witch one is exchanges. But a clear indicator is if the address receives stake rewards.
So if you click on the second largest wallet showing on BE's richlist (GYkj5Pwg5thcyzTWFC7MDsK5hYRidBjFd6). You can see it receives 25 coin stake rewards, and that means its a person staking those coins and it cant be an exchange.
Looking very good dev, can't wait to test it out! Keep on with the awesome work
If the guy asking above here reffered to the richlist in block explorer. It can be difficult to know witch one is exchanges. But a clear indicator is if the address receives stake rewards.
So if you click on the second largest wallet showing on BE's richlist (GYkj5Pwg5thcyzTWFC7MDsK5hYRidBjFd6). You can see it receives 25 coin stake rewards, and that means its a person staking those coins and it cant be an exchange.
Looking very good dev, can't wait to test it out! Keep on with the awesome work