A relief rally on Monday masked a pretty slow week on Wall Street this week. The Dow Jones Industrial Average (^DJI 0.56%) gained 182 points Monday after Crimea voted to join Russia in a highly questioned referendum, but the vote didn't seem to spark fear of violence either within the region or from Western forces. Just the idea that conflict could be avoided with the world's No. 1 oil producer, Russia, was enough to get the market off on the right foot.

Stocks fluctuated the rest of the week and gained 1.48% in total. The Federal Reserve tapered its bond-buying program again to $55 billion per month, but there wasn't much in the way of market rattling news. But that doesn't mean we didn't have some big winners on the market this week.

UnitedHealth Group (UNH 1.61%) was the Dow's top stock, rising 7.5% for the week. There was further momentum of people signing up for health plans through "Obamacare," and there are even signs that it will increase profits for health insurance. First, a report by the Kaiser Family Foundation showed that market share leaders before Obamacare are remaining market share leaders today. The winners on a state-by-state basis may shift slightly, but UnitedHealth Group and others don't look like they'll lose too many customers to smaller competitors.

From the profit side, WellPoint said this week that it's expecting profits to exceed $8.20 per share from previous guidance versus at least $8.00 per share in previous guidance. The addition of 1 million to 1.3 million net new customers was cited as a main reason for the higher profit. Maybe Obamacare can be good for insurers after all.  

Microsoft also lowered the price of Xbox One Titanfall bundle $50 to $450 in response to Playstation 4. Image owned by The Motley Fool.

Microsoft (MSFT -1.27%) was the Dow's second best performer, gaining 6.5%. Rumors swirled earlier this week that new CEO Satya Nadella's first major move would be introducing Microsoft Office for the iPad, the world's most popular tablet. Office is a cash cow for Microsoft and the iPad is a huge opportunity, especially because Apple is now giving away its productivity software with new devices. The move would also signal a willingness to work with non-Microsoft products, which may be key as tablets and smartphones run on non-Microsoft software become more common.  

JPMorgan Chase (JPM 2.51%) rounds out the top Dow stocks with a 5.9% jump this week. The company passed the Federal Reserve's latest stress test, indicating that it could continue to borrow in a deep recession, and announced the sale of its physical commodities business for $3.5 billion. The sale doesn't get the company out of commodities entirely, but it could ease pressure from regulators who think the largest commodity traders are manipulating the market.