This report, from the Institute for Supply Management, is among the most-watched economic surveys by stock and bond traders because a) it is one of the first to come out each month, b) it is a great gauge of the U.S. economic health, c) it has been a consistent measure for decades, and d) is from the private sector, so the government can't manipulate the numbers.

The ISM Report on Business grew from a small-scale survey in 1931 to a snapshot that encompasses more than 300 companies in a wide range of industries. The ISM polls business managers, asking them to evaluate changes in factors like production, new orders, inventories and prices and contrasts them with their answers from the previous month. Then, the answers are crunched and spit out as an index. If the number comes in north of 50, it suggests the economy is expanding (a good sign). Under that level, and it's shrinking (not so good).

Traders love this report because it usually sets the tone for all the other data that is released each month. (Only the monthly federal Employment Situation report tends to have as much impact on the markets.) Sometimes, its components are more important than the whole. If stock and bond traders are worried about inflation, they'll look at what the survey said about the prices companies are paying for goods and the wages they're paying their workers to see signs that prices might be rising.

The ISM figures originally tracked just manufacturing data, but the group started polling service industries in the 1990s. That report, though, doesn't have the same market punch as the manufacturing numbers, but could as the service economy continues to grow in the U.S.

We end on a historical note: For years, the ISM numbers were actually known as "napalm," because the ISM used to be the National Association of Purchasing Managers. But many in the market (and in the organization itself) weren't keen on being associated with a Vietnam-era weapon.