Even though this was a short week of trading because of the Thanksgiving Holiday, with volumes low on Wednesday and the half-day of trading on Friday, the Dow Jones Industrial Average (^DJI -0.57%) had a really good week. The Dow started Monday morning at 12,590, and as the closing bell rang at 1 p.m. ET on Friday, the index had moved up to 13,009, a 3.3% increase in just three and a half days. The two biggest moves higher came on Monday and Friday, days when the market moved higher by 205 points and 172 points, respectively.

Both the two other major indexes followed the Dow's lead this week and posted sizable returns for investors. The S&P 500 (^GSPC -0.35%) moved higher this week by 50 points, or 3.6%, and closed above 1,400 for the first time since early November. The Nasdaq (^IXIC -0.31%) also showed nice gains this week, increasing by 80 points, or 2.77%.

Even with continued concerns over the fiscal cliff, the problems in the Middle East, and mixed economic data released this week, investors who have money sitting on the sidelines really missed out. Long-term-thinking investors know and understand that the market may make moves lower in the short term, but over the years, it will rise higher. These same investors don't attempt to predict market moves, because they understand that it's not possible and that in attempting to do so, over time they will miss more market moves than they catch -- ultimately depressing their returns and causing more headache than it's all worth.

While shareholders of most of the Dow components saw their investments increase in value this week, one company had its stock bashed. Hewlett-Packard (HPQ -0.28%) was the worst-performing Dow component this week. When the markets opened on Tuesday, the stock price was down 10% from where it started on Monday morning. And even though shares moved higher by more than 4% in just the few hours the market was open on Friday, the stock still ended the week down 4%. While Hewlett-Packard announced disappointing fourth-quarter results on Tuesday morning, the stock price was probably more affected by the announcement that the company will take an $8.8 billion writedown for software company Autonomy. HP purchased the U.K.-based company a little more than a year ago for $9.7 billion. Meg Whitman, HP's CEO, said on Tuesday that the company is looking into suspicious accounting practices that Autonomy was using before the HP buyout.