The Dow Jones Industrial Average (^DJI -0.98%) and S&P 500 are both just under breakeven at the end of a holiday-shortened trading week. The Dow jumped more than 122 points yesterday to begin the famed "Santa Clause rally" of stock jumps between Christmas and the new year, when volume can be extremely light. But that rally is taking a rest today.

Retailers are ending a rough week that revealed more about Target's (TGT -0.54%) data breach and left many people without gifts due to UPS (UPS 0.53%) delays.

More Target data stolen
Today, Target said that "strongly encrypted PIN data" was also stolen when up to 40 million credit and debit card accounts were hacked during the intense shopping period after Thanksgiving. The nation's No. 2 discount chain insisted that "PIN numbers are safe and secure," but this is no doubt another PR nightmare it doesn't want to deal with.

Long term, I don't think this will keep customers out of Target stores; but over the next few months there's a lot to do to make consumers feel safe shopping there.

UPS delays Christmas
On Twitter, #UPSFail has been trending in the last couple of days as shoppers vent about gifts that arrived later than promised. Amazon.com (AMZN -1.65%) was one of those affected because it relies on UPS and FedEx to execute its Amazon Prime two-day shipping promise. I happen to be one of those who got gifts late (by three days) from Amazon via UPS, and the broad shipping miss raises long-term questions about the membership-based Prime program.

Amazon is highly reliant on UPS and FedEx to deliver packages to meet its two-day pledge, and this year it appears UPS simply didn't have the capacity to cope with the deluge of late orders. It also shows why Amazon is testing alternative shipment methods like drones.

This is a black eye UPS doesn't need as online retailers choose which shipping partners to grow with over the next few years.

More questions than answers
This holiday season has been full of turmoil for retailers. Brick-and-mortar stores had to discount heavily to generate sales, Target faced a major security breach, while Amazon failed to meet its two-day shipping standard for a chunk of its Prime members.

We know that Amazon will outgrow most other retailers, but there were few all-out winners this holiday season. It's a tough time to be a retailer, no matter what part of the market you serve.