With gains of almost 30% since November, it's been one of the better multi-month runs in the S&P 500 in recent memory. It's looking increasingly likely that inflation has been tamed by a Fed that's managed to thread the needle and get it under control without causing a recession. Most stocks have been enjoying a widespread boom as a result. 

But with such solid, and in many cases one-way, gains in recent months, there's an argument to be made that some stocks are starting to look a little overheated. One way to see this is through a stock's relative strength index (RSI). The RSI considers a stock's recent trading momentum and spits a reading between 0 and 100, indicating whether a stock is overbought or oversold; readings above 70 suggest overbought conditions, while readings below 30 indicate oversold conditions.

A heavily oversold stock can often offer an interesting buying opportunity, while a heavily overbought stock can often warrant caution. However, looking for stocks that meet the latter criteria can often turn up stellar names that look a little frothy but hold some of the most remaining upside. Let's take a look at 3 such names. 

EMCOR Group, Inc (NYSE: EME) 

Emcor is a $16 billion engineering and construction company based in Connecticut, and its shares have been on an absolute tear since the start of the year. Having already logged an impressive 2023, with gains of 120% in the second half alone, they've since added a further 70%. 

The stock's RSI has been above 70 since the middle of February, which interestingly has done little to slow down the relentless march north in the meantime. This goes back to our earlier point of a red-hot RSI, often suggesting there's a ton of upside yet to be realized. 

Yesterday saw shares log just their seventh red day since February, and the MACD has registered a negative crossover, so we could be looking at a timely pause. For those of us on the sidelines, this could be perfect timing, as some profit-taking now would be healthy, as it'd set Emcor shares up for further gains after some consolidation. 

Textron Inc. (NYSE: TXT) 

Like Emcor, shares of Textron have been rallying hard since the first weeks of 2024, gaining as much as 25% in that timeframe. Much of the gains came from news that the U.S. military was starting to resume its use of Textron aircraft and equipment, having previously had it all grounded following a series of fatal crashes. 

The aeronautical and industrial giant's RSI was as high as 82 coming into the start of this week, but interestingly, the past few sessions have seen it take its first breather in a long time. With Citigroup reiterating their Buy rating on the stock just yesterday while simultaneously boosting their price target to $111, you have to be thinking that this week's profit-taking is starting to look like a serious entry opportunity.

Marathon Oil Company (NYSE: MRO) 

Shares of Marathon Oil have gained some 35% since January, logging NYSE: MRO" target="_blank" rel="noopener">an incredible record of just 15 down days in more than three months of trading. But all that upward momentum has pushed the stock's RSI up to 88, an eye-watering level that screams overbought - at least in the near-term. 

But bullish analyst upgrades in recent weeks, off the back of what's been called a "strong financial foundation, low debt levels, and robust free cash flow yields," suggest further gains are imminent. 

Last month alone saw the Royal Bank of Canada reiterate its Outperform rating on the energy stock, the team at Argus upgrade it to a Buy, and the teams at Morgan Stanley, Goldman Sachs, and Mizuho all boost their price targets. Like with the other two on this list, a little bit of profit-taking over the coming sessions would be no bad thing, so plan your trade and potential entry points accordingly.