Yes, In this case your money is more safe if you invest in Bitcoin, Ethereum, Litecoin, Dash, Monero and Ripple. Coins with lower market caps can be easily manipulated by whales and investing in them is like a gamble.
man bitcoin is also being manipulated haha, but i guess it is a good one because it gives you so much value with its massive price pumps
every market has its manipulations. there are no exceptions in the real world.
what matters is that how much a market is manipulated and how successful it is. i would say for bitcoin the success rate is small and it is shrinking as bitcoin grows bigger.
but for altcoins it is extreme because when someone simply has millions of some coin out of thin air (eg. premining it) that is not a fair market you can play with. you either have to stay away or go with the wave and dump before the whales do.