Your friend probably doesn't even know that the sushiswap dev dump $8 million tokens. He's trying to pull a Charlie Lee if you know what I mean. Many of the previous supporters have lost confidence because of what he did. You know what happens to projects like that? It drops tremendously.
Binance just listed that token because they want the trading fees from users like your friend who are riding the DeFi hype. Not all projects in there are legit and if you want to check how it's performed after the hype -
https://coinmarketcap.com/currencies/sushiswap/historical-data/ If you're going to buy now, you're only giving your money to the people who are waiting to dump and exit. Careful.
If this is the case then its better to stay away to this project and find another that is worth to invest your money.
Dumping $8 million tokens has an impact to its price and probably those who buy at higher are just waiting to sell and get their money back.
Do a research before investing.