My gut feeling says it depends on the trading strategy of the firm they used for the testing. Traders don't need a bull market to make money, they just need ma

My gut feeling says it depends on the trading strategy of the firm they used for the testing. Traders don't need a bull market to make money, they just need market volatility. If the market is going up they can bet on the value of stocks increasing, if the market is going down they can bet on the value of stocks going down. If the firm has a policy of being long only and traders have to hold their trades for a long time then yes, the direction of the market is going to affect the performance of traders. More information about trading strategy and limitations are necessary to really tell.