It depends on time/market situation I think. sometime Holders can earn huge profit and sometime trader. In bullish market holder can earn huge profit and in bearish market trader can earn profit than holders I think.
it depends not only on market conditions but on trend conditions that can help to make prices move up and down, when like today I see the trend going up and many traders will benefit from cryptocurrency price increases.
Yes, it is impossible for us to say, who is going to benefit from the coins they are holding. Already we are seeing slowly the prices are recovering in terms of USD value but not in terms of prices. So definitely people who are holding potential coins will always help them to make some decent profit in the market.