Last week was one of the busiest in a long while for the stock market. We learned that the Federal Reserve will continue to taper its monthly bond purchases. We learned that pending home sales have thankfully picked up. And we learned that the unemployment rate dropped in April to 6.3%, the lowest rate since the middle of 2008.

But none of these things are to blame when it comes to the performances of Bank of America (NYSE:BAC) and Best Buy (NYSE:BBY), which sank and soared over the past five days, respectively. Bank of America finished the week down by 4.4% while Best Buy was up 7.3%.

For Bank of America, the week couldn't have started on a worse note. On Monday, the nation's second largest bank by assets announced that it had suspended its recent dividend increase at the behest of regulators. The problem stemmed from an accounting error that led Bank of America to overstate its regulatory capital levels.

The news hit the bank's stock hard, sending shares down by more than 6% on Monday and causing analysts to second guess their confidence in the Charlotte, N.C.-based lender. Among others, CLSA's Mike Mayo recommended that investors sell their shares in Bank of America and replace them with, of all others, Citigroup, which, it's worth noting, has also had its 2014 capital plans rejected by the Fed.

BAC Chart

"One of our questions at the coming May 7 annual meeting is whether [the bank] is too big to manage," Mayo wrote to clients shortly after Bank of America's disclosure on Monday.

Meanwhile, on the other end of the S&P 500's (SNPINDEX:^GSPC) spectrum of performances, shares of Best Buy soared last week, posting gains in all five trading sessions. To be clear, the precise catalyst for the climb remains to be seen. While shares are down by 36% since the beginning of the year, they're nevertheless up by 18% since the middle of 2012.

BBY Chart

The ailing electronics retailer has struggled to compete against the likes of and Costco, both of which are able to sell many of the same goods as Best Buy at considerably reduced prices. This reality has forced the company to experiment with alternative models.

Most recently, it was announced on Thursday that Sony would join Samsung, Apple, and others by opening dedicated vendor showcases in Best Buy locations. The objective is to drive traffic into the stores and then convert the flow into paying customers. While it remains to be seen whether this will work, it's certainly an understandable tactic for a company that's falling further and further behind competitors.

John Maxfield has no position in any stocks mentioned. The Motley Fool recommends and owns shares of, Apple, Bank of America, and Costco Wholesale. Try any of our Foolish newsletter services free for 30 days. We Fools don't all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.