It's not often that bullish investors are disappointed with a 106-point gain for the Dow Jones Industrials (^DJI 0.34%), especially one that leaves the average at an all-time record high. But with early gains that were more than double that, the triple-digit gain for the Dow was a bit of a letdown, especially in light of favorable domestic data on home prices and consumer confidence. Yet good news on the economic front has been no guarantee of stock market success, given that investors are more concerned about the timing of the exit of the Federal Reserve in its bond-buying operations and other monetary-policy machinations. On that front, bond prices plunged today, with the 10-year Treasury yield rising above 2.1% for the first time in more than a year.

Moreover, several stocks posted substantial declines. Leading the way was AT&T (T 0.58%), which dropped 1.5%. Fool contributor Travis Hoium earlier today highlighted the threat to AT&T and rival Verizon (VZ -0.47%), which also fell more than 1%, noting that initiatives from Google could eventually threaten their entire business models. However, another reason for the drops is that telecom stocks are traditionally sensitive to interest rate fluctuation, as their dependable flows of customer subscription revenue closely resemble a bond-like income stream. If bond yields keep rising, then investors will want higher dividend yields from AT&T and Verizon, and that in turn will send shares lower.

Consumer giant Procter & Gamble (PG -0.13%) also fell today, posting a 1.25% decline. After soaring on Friday after news that the company had replaced its CEO with former top executive A.G. Lafley, P&G's stock might have reacted to the realization that the return of its former CEO won't necessarily vault the consumer-products company back to complete health without a substantial struggle. Lafley's main advantage is his knowledge and familiarity with the company, but P&G needs innovative products that will reestablish its leadership in the industry.

Finally, Exelon (EXC -0.10%) plunged 7.5% after getting downgraded by Deutsche Bank. The analyst highlighted a poor capacity auction last Friday as driving prices lower through 2016 or 2017, and with the continued pressure of low-cost natural gas for electricity production, Exelon won't be able to fully reap the benefits of the cost advantages that its nuclear power capacity often produces. Rising bond yields also take their toll on utilities, further exacerbating the declines.