After yesterday morning's plunge and late-in-the-day rally, JPMorgan Chase (JPM -0.14%) jumped in overnight trading and has tentatively staked a spot in the green: up 0.60% around midday. This is better performance than two of its Big Four brethren, but don't expect it to necessarily hold through the end of trading.

Through the looking glass
The sector is mixed, and markets are mixed. At the time of writing, JPMorgan is up, as is Wells Fargo, but both Citigroup and Bank of America are down. As for the markets, both the S&P 500 and the Dow Jones Industrial Average are down, while the Nasdaq Composite is just barely keeping its head above water.

We can look to the Federal Reserve for the vague feeling of uncertainty in the markets. With overall strengthening economic data, there's concern the Fed is going to begin tapering back its massive monthly bond purchases, which is widely believed to be behind the nascent U.S. economic recovery.

The concern is warranted: Bernanke and company have made it clear they want to slow down quantitative easing as the economy improves. It's a double-edged sword. If the economy shows signs of improvement, there's fear Fed support for the economy will slowly begin disappearing, and investors will pull back.

But signs of continuing economic weakness mean the likely continuation of the Fed's easy money policies, keeping investors in the markets. So some weak manufacturing data released yesterday actually fueled the markets' rally.

Foolish bottom line
There's no breaking news for JPMorgan that's going to swing it one way or the other today. It will likely ride whatever wave the market throws at it. Often times, it's difficult if not impossible to ascertain the exact reason for a stock's daily move, which is why here at The Motley Fool, we stress a long-term view of investing.

Day to day, week to week, and even month to month, stocks can gain or lose for no seemingly good reason. Tune out the market noise and tune into the fundamentals of the companies you're invested in -- and leave the constant ticker checks to the day traders: Your portfolio will thank you, even if your broker won't.