if you buy when the market is green it is likely to spend more capital to buy altcoins, and that does not guarantee you will return the capital in the near future if prices continue to rise, it is likely that you will profit. if after buying a few days later the price continues to decline you will experience a loss. because the price of digital / crypto money tends to fluctuate. my advice is better if you buy altcoins when the market price is down and you can resell when prices rise.