If there was an overriding factor moving the stock market last Thursday, it was crude oil.

The price of a barrel plunged 4.9% as commodities traders saw winter stockpiles of crude and heating oil expand rapidly. After peaking at about $55 a barrel in late October, oil prices had swooned 22.3% by Thursday's close.

The decline had an immediate effect on energy stocks, which sold off broadly. But one of the industries investors shifted their money into was airlines, which suddenly saw a major portion of their operating costs — fuel — precipitate. And so it was that two of the 10 stocks to which the big money moved into last Thursday were airline stocks, both on volume more than three times their average.

These types of volume surges can mean only one thing: Institutional investors grabbed handfuls of shares, their action revealed by the relatively heavy trading that took place.

Another area of strength Thursday was technology, where a chip designer and a data-storage company met enthusiastic buying.

Stocks that went public this year have also acted generally well. From that group, we found three stocks making the list of 10 stocks rising on unusually heavy trading: the chip company, an innovator in wound treatment and a firm that manages and invests in the booming real estate market.

A casual observer of the stock market might dismiss airlines (figuring the industry is trashed) or IPOs (just because they haven't been around the market long). But when the stock market keeps sending a stock higher on heavy volume, it's hard to argue with the tidal wave of institutional demand. Investors would do well to let go of their own instincts and watch what the market is signaling).

Why 'Big Money' Moves Are Critical

The moves of mutual funds, insurance firms, hedge funds and other institutional investors carry extra weight in the stock market. That's why Investor's Business Daily's "Where The Big Money's Flowing" was designed to help detect institutions' moves.

Institutions trade in large sums of money and large blocks of shares, dwarfing the action of individual investors. An institutional purchase or sale of a stock usually means thousands of shares and millions of dollars moving the stock. Moreover, an institution must commit itself to spend days, weeks or even months to fulfill its goal.

That's called accumulation, and it is one of the most important signs that a stock is likely to keep moving higher. Because the accumulation takes place over prolonged periods, it's probable the stock will make a significant advance thanks to those institutional traders who are buying.

IBD tracks unusually high volume moves each day in "Where The Big Money's Flowing." Placed next to the paper's stock tables, this screen has signaled the earliest stages of most leading stocks' price surges. It is also helpful in detecting early signs of distress in a stock. When institutions start pulling money away from a stock, they also create a heavy-volume wake that's reflected in “Where The Big Money's Flowing”, only on the "down" side of the list.

By comparison, the most-active lists on most newspapers and financial Web sites merely give the stocks with the largest amount of shares traded. The mega-capitalization stocks usually dominate these lists, and they offer no help at all in determining which stocks had unusual volume spikes.

On IBD's Web site, www.investors.com, a similar table with a similar name ("Where The Big Money's Flowing Now") is updated throughout the trading session.

Back to the Special Edition: 10 Stocks Rising on Unusual Volume.