For instance, if you currently have $26,000, you could invest in 1 BTC and hold it from now on. Hold it until BTC surpasses its previous peak of $69,000, which would mean your asset is now worth $69,000. At this point, place the value of 1 BTC into Cross Margin and borrow $30,000 to invest in Altcoins. Borrow only $30,000 or even less, not more. This way, you can continue holding onto that 1 BTC as it climbs to $100,000 or $150,000, while also having $30,000 to invest in Altcoins. With the $30,000 borrowed, smart investment in Altcoins can potentially turn your initial asset into $300,000. You could sell the original 1 BTC that you held onto for $100,000 or $150,000. The combined profit from BTC and Altcoins could amount to around $400,000 - $450,000. After repaying the $30,000 borrowed from the exchange, you'd be left with $370,000 - $420,000.
You only assume that Altcoin will continue to pump right after you manage to get profit from Bitcoin by hitting the previous peak. The calculation is very exaggerated since the only potential growth of Bitcoin that time will be only small since it pumps along with Bitcoin and there’s a low chance that Altcoin extend further it pump after Bitcoin slow down.
Using cross margin is not a bad idea but doing it while most of the token is already pump hard will give the chance to liquidate your hard earned capital since you use it as collateral.