General Mills (GIS) reported its first quarter financial results on Wednesday. Both revenue and net income declined, with both missing analyst estimates.

General Mills posted earnings of $352.4 million, or 55 cents per share, down from $468.1 million, or 70 cents per share in the same quarter last year. Excluding special items, earnings were 61 cents per share, below analysts’ view of 69 cents.

Revenue dipped 2.4% to $4.27 billion, from $4.37 billion last year. Wall Street analysts expected to see revenue of $4.38 billion.

The company saw downside in its U.S. Retail segment, but reported increased sales in its consolidated international businesses.

Although GIS reaffirmed its constant currency growth for 2015, it noted that the U.S. market has becoming much more challenging than originally expected.

General Mills is not the only company struggling in the cereal business. Kellogg Company (K) has also reported weak sales for cereal. When K reported earnings in July, its CEO John Bryant noted that the cereal segment has “remained challenging.”

The decline of the cereal market is far from breaking news. Overall, cereal sales have been falling for a decade as consumers are now reaching for quicker meals or healthier options.

On Wednesday, both General Mills and Kellogg Company were downgraded at Societe Generale. The firm lowered its rating on GIS from “Hold” to “Sell” and gave the company a $50 price target.

Kellogg Company was cut from “Buy” to “Hold” and was given a $66 price target. The analyst noted that K’s cereal business could take multiple years to turn around.

As the cereal business continues to show a decline, it is important for mutual fund investors to be on watch for the biggest holders of these companies.

Mutual fund investors should be aware of the performance of the major holdings in the the funds that they own. Earnings reports, such as today’s release from General Mills, are a great way to measure holdings.