When it comes to Investing, it is always good to start by checking out what you want or in this case the type of altcoin you want, and then studying all you can. Most advising people about the type of altcoin to invest doesn't always end well especially when it doesn't go as planned with respect to the nature of the crypto space. Nevertheless, if am to point out my opinion, major altcoins aren't losing value rather they are still dominating and thus good for long term investment; such major altcoins are Ethereum (ETH), Stellar (XLM), Binance Coin (BNB), ADA and maybe LTC. Lastly, holding BTC is also a good investment call.