New Delhi, March 27 -- Everyone loves an underdog, but doing so may have been costly recently.

For a long time, one popular method of portfolio management required taking profits in winners to lock in gains and reduce risk, while using some of those funds to buy laggards that nonetheless appeared to have strong fundamentals that could trigger a rebound. This contrarian rebalancing tactic of selling top performers to pay for new bets adds "modest value over the long run," writes Trivariate Research President Adam Parker.

However, one big caveat is that this strategy isn't a one-size-fits-all approach, and in momentum-driven markets-like the one that has been dominant in recent years-it's actually a headwind.

That's Parker's conclusion a...