Trading will help you in increasing your coins in your wallet, so its always better to trade with them instead of simply holding, as holding will not grow your coins.
Trading / Gambling.etc are not advisable with Bitcoin. The chances are that you may lose more than what you are going to gain. Holding the coins is the best option. Because unlike fiat currency, BTC is not affected by inflation. Its value is not going to decline if you hold. Just keep them safely, in offline storage with multiple wallets.