The recommendations of Wall Street analysts are often relied on by investors when deciding whether to buy, sell, or hold a stock. Media reports about these brokerage-firm-employed (or sell-side) analysts changing their ratings often affect a stock's price. Do they really matter, though?

Let's take a look at what these Wall Street heavyweights have to say about Sony (SONY) before we discuss the reliability of brokerage recommendations and how to use them to your advantage.

Sony currently has an average brokerage recommendation (ABR) of 1.20, on a scale of 1 to 5 (Strong Buy to Strong Sell), calculated based on the actual recommendations (Buy, Hold, Sell, etc.) made by 10 brokerage firms. An ABR of 1.20 approximates between Strong Buy and Buy.

Of the 10 recommendations that derive the current ABR, nine are Strong Buy, representing 90% of all recommendations.

Brokerage Recommendation Trends for SONY

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The ABR suggests buying Sony, but making an investment decision solely on the basis of this information might not be a good idea. According to several studies, brokerage recommendations have little to no success guiding investors to choose stocks with the most potential for price appreciation.

Do you wonder why? As a result of the vested interest of brokerage firms in a stock they cover, their analysts tend to rate it with a strong positive bias. According to our research, brokerage firms assign five "Strong Buy" recommendations for every "Strong Sell" recommendation.

This means that the interests of these institutions are not always aligned with those of retail investors, giving little insight into the direction of a stock's future price movement. It would therefore be best to use this information to validate your own analysis or a tool that has proven to be highly effective at predicting stock price movements.

Zacks Rank, our proprietary stock rating tool with an impressive externally audited track record, categorizes stocks into five groups, ranging from Zacks Rank #1 (Strong Buy) to Zacks Rank #5 (Strong Sell), and is an effective indicator of a stock's price performance in the near future. Therefore, using the ABR to validate the Zacks Rank could be an efficient way of making a profitable investment decision.

ABR Should Not Be Confused With Zacks Rank

Although both Zacks Rank and ABR are displayed in a range of 1-5, they are different measures altogether.

The ABR is calculated solely based on brokerage recommendations and is typically displayed with decimals (example: 1.28). In contrast, the Zacks Rank is a quantitative model allowing investors to harness the power of earnings estimate revisions. It is displayed in whole numbers -- 1 to 5.