Red-hot momentum in a stock can make you giddy with excitement, but sometimes the price rally isn't sustainable and the stock becomes overvalued and ripe for a fall.

Insurance broker Arthur J. Gallagher & Co. (AJG) - Get Report is one such overvalued investment. Up 17.73% over the past three months and less than a stone's throw away from its five-year highs, this stock is going fast, but could soon run out of steam. The stock is being added to the S&P 500, but don't let that fool you: this Wall Street darling is dangerous right now.

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Below, we pinpoint an ingenious method that allows you to make money on a rising or falling stock, but first, let's look at what's wrong with AJG.

Arthur J. Gallagher & Co. replacedCoca-Cola Enterprises Inc. on the Standard & Poor's 500 index from May 27. Coca Cola Enterprises is reported to be merging with two other Coca-Cola bottlers to form a new company called Coca-Cola European Partners, a company to be located in Spain and consequently ineligible for continued inclusion in the S&P 500.

Gallagher plans, designs, and administers a wide variety of customized property/casualty insurance and risk management programs. The company also provides a broad range of risk management services.

The company produced approximately 70% of revenues for the combined brokerage and risk management segments domestically, with the residual 30% derived internationally, primarily in Australia, Bermuda, Canada, the Caribbean, New Zealand and the U.K. (based on first quarter 2016 revenues).

The company operates via three reportable segments: brokerage, risk management and corporate, which contributed approximately 63%, 14% and 23%, respectively, to sales during the three-month period ended March 31, 2016.

Additionally, its main sources of operating revenues are commissions, fees and supplemental and contingent commissions from brokerage operations and fees from risk management operations. Investment income is generated from invested cash and fiduciary funds, clean energy and other investments, and interest income from premium financing.

Now let's get down to the meat and potatoes of our argument. To safely buy the stock now, you'd require comfort on three factors:

1. Earnings: Arthur J Gallagher & Co. is projected to clock 9.29% earnings-per-share (EPS) growth per annum for the next five years. This is slower than the 14.23% run-rate for the previous period. The 9.29% rate is hardly above the industry average or the likes of Aon plc (9.34%). Also, Gallagher's projected growth is markedly slower than competitors Marsh & McLennan Companies (11.27%) and Willis Towers Watson (32.16%).

2. Valuation: We generally use price-to-earnings growth (PEG) ratios (five-year expected) to judge whether a stock is exorbitantly priced or a good value for your money. Arthur J Gallagher & Co. sports a PEG ratio of 1.83, higher than Marsh & McLennan Companies (1.72), Aon plc (1.75) and Willis Towers Watson (0.54). Since the stock's run up fast, there's hardly space for more upside.

3. Target price and dividends: Analysts have a 12-month median price target of $51 for AJG stock, translating to just a 5.7% increase from the last price. This is too meager by far. On the dividend front, the 3.15% yield and five years of dividend growth are good for those seeking passive incomes, but if you're looking for long-term capital appreciation, this stock isn't worth the price.

Arthur J. Gallagher & Co. doesn't make a great investment if price upside is your primary goal. Its dividends offer a nice opportunity, but if income-generation were your only investment drive, there are other contenders you could go with: dividend aristocrats like AT&T, Consolidated Edison, and AbbVie promising higher yields and safer dividends.

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As you can see, Arthur J. Gallagher is a poor choice for your investment cash. But even if you're feeling wary of the stock market as a whole these days, there is a great way to earn extra income without touching stocks. In fact, by using this easy technique, you could rake in an extra $67,548 over the next 12 months -- GUARANTEED. Click here now for all the details.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.