I am more comfortable with the price of bitcoin and how I do gradually trade bitcoin than any other assets out there, though I don't know gold is being manipulated but for bitcoin is somehow possible to trade on it after making your research to see if there's good news that could push the price above expected, though it could be traded different ways either again the market or toward the market. Like when Green and or when Red. But most option traders do like trading when it's on red.
Gold, stocks, real estate markets are all manipulated. In any free market, we always have big investors and retail investors, professional traders and amateur traders, there are manipulations from professional institutional entities to direct the market toward their plans and get profit.
When you spend your money to invest, focus on long term, you will be less affected by manipulations in the market. Gold, stocks, real estate, Bitcoin, if you use own pocket money to invest for long term, you will get profit and are likely immuned against manipulations in short term.
It certainly depends on individual's preference. If you are a low risk taker, prioritize gold investment over bitcoin, since it's less volatile and is most likely to give fixed profits in the future. However, if you are a high risk taker, bitcoin is the best option.
If you are a high risk taker, and want to use high leverage for your trading position, Bitcoin is still a safest choice for you. Because Bitcoin is a leader in this cryptocurrency market and if Bitcoin falls 10%, altcoins will fall -20% or -30% or deeper. If you take a same high leverage with Bitcoin and altcoins, you will have bigger risk of liquidations on your positions in altcoin than in Bitcoin.