First-quarter earnings season for the 30 stocks in the Dow Jones Industrials (^DJI 0.69%) is just about over, with just a few stragglers left to report in the weeks to follow. In general, the season has been a good one for investors, with many more positive surprises than negative ones for Dow investors.

But several stocks have stood out for their extraordinary performance compared to what investors expected of them. Let's take a closer look at the four companies that beat their earnings expectations by the greatest margins.

Travelers (TRV 0.02%)
For insurance giant Travelers, all it took for a big beat was for the company to avoid a major catastrophic event. The company reported an 11% jump in earnings and a record operating profit, beating expectations by $0.29 per share and boosting its dividend.

Travelers has faced a lot of pressure in recent years, with two major hurricanes in two years and ongoing low interest rates hurting investment returns. But the upside of the big losses has been that Travelers has been able to increase the premiums it charges for insurance coverage, and that played a big role in the positive quarter.

Boeing (BA -0.76%)
Boeing has been in the headlines for all the wrong reasons in 2013, with the ongoing travails of its 787 Dreamliner. Yet those troubles didn't weigh down earnings, which managed to beat expectations by $0.25 per share and reaffirm its earnings guidance for the full 2013 year.

The future for Boeing looks even brighter, as modifications to the Dreamliner's batteries should have the 787 program back on track in short order. Once the company puts the troubling episode behind it, Boeing will simply need to focus on meeting its production commitments and delivering on an impressive backlog of orders that extends years into the future.

JPMorgan Chase (JPM 1.44%)
The big Wall Street bank managed to beat expectations by $0.20 per share thanks to a 33% jump in net income from the year-ago quarter, setting a new record. Improving credit quality also bolstered the company's prospects, allowing it to increase its dividend.

Yet longer term, concerns still remain. Revenue fell almost 4% as falling net interest margins resulted in less interest income. More notably, mortgage fees dropped even as the number of loan originations increased, and with refinancing activity likely to fall as interest rates approach a bottom, JPMorgan could face further revenue challenges that will be likely to fall to the bottom line in the future.

Alcoa (AA)
Alcoa is a small player in the Dow, so all it took was a small beat in absolute terms to equate to a big earnings surprise for the company on a percentage basis. Strong demand for aluminum wheels and aircraft parts resulted from a healthy market in the automotive and aerospace industries, and Alcoa took full advantage of those pockets of strength in overcoming some of the challenges that have resulted from overall weakness in prices for aluminum.

Alcoa's woes are far from over, as it looks at potentially idling more of its production plants in light of low prices. Yet if recent economic news results in a global economic boost, then Alcoa has positioned itself as well as possible to benefit.

Stay tuned for more surprises
Stocks rarely match expectations perfectly, so keeping your eyes open for unexpected positive surprises is important. Often, unexpected news will change your views on a stock in either direction, and not taking action will cause you to miss out on a lucrative opportunity.