With the November rally in the SPDR S&P 500 ETF Trust (NYSEARCA: SPY), a number of large-cap stocks are in buy range. Among those names are three large companies that are not S&P 500 components: Li Auto Inc. (NASDAQ: LI), MongoDB (NASDAQ: MDB) and Novo Nordisk A/S (NYSE: NVO).

In 2023, large caps have outperformed small caps and mid caps, with the S&P 500 outperforming the Russell 2000 small-cap index, tracked by the iShares Russell 2000 ETF (NYSEARCA: IWM) by a wide margin. 

When tracking stocks showing outperformance, relative strength becomes an important technical indicator. Relative strength gauges a stock's performance against its peers or market indexes. It's helpful in showing a stock's resilience during market fluctuations and allows investors to identify outperformers. 

Relative strength gauges price momentum

When you see a stock with exceptional relative strength, that suggests robust momentum and the potential for even more gains. The Relative Strength Index, an often-used technical indicator, is an easy way to gauge the speed and the magnitude of a stock's price movements. 

For example, you can see the relative strength index on the Li Auto chart to get a visual representation of the stock's price performance. Its RSI stands at 47.26 as of the close on November 24. That number indicates that the stock is neither overbought nor oversold.

The MongoDB chart and the Novo Nordisk chart also indicate these stocks' upside momentum relative to the market. But you can also use them to determine potential buy points.  

Li Auto

The Chinese EV maker has been forming a cup-shaped pattern since August, below a high of $47.33. Li and fellow Chinese company XPeng Inc. (NYSE: XPEV) are price leaders among automotive stocks.

The company has a stellar record of revenue and earnings acceleration. MarketBeat's Li Auto analyst forecasts show a consensus view of "buy" with a price target of $70.42, for a healthy upside of 70.64%. 

As you can see, analysts believe the stock can not only break out of its current base but rally far beyond it. Currently, the most conservative buy point for Li Auto is that prior high of $47.33, but a trend line connecting a series of recent lows suggests an earlier buy point at $42.50. 

Li Auto has posted five weeks in a row of upside trade, with heavier-than-normal volume in two of those weeks.  

MongoDB

Part of the red-hot database sub-industry within tech, MongoDB's fellow top large-cap performers include Splunk Inc. (NASDAQ: SPLK) and S&P component Oracle Corp. (NYSE: ORCL).

MongoDB's revenue has grown at rates of 29% or higher in the past eight quarters, while earnings have been growing at triple-digit rates recently, as the company notches profits after years of losses. 

Those losses weren't particularly unusual, as MongoDB is still a fairly young company, having gone public in 2017. Newer public companies often prioritize growth over immediate profits, reinvesting earnings into expansion. This strategy aims to capture market share before prioritizing profitability, and investors understand this.

However, with annual profitability in sight, investors have been sending the stock higher, more than doubling in price year-to-date. The current buy point is the stock's July high of $439, although the stock could potentially form a handle that would offer an earlier entry.

Novo Nordisk

The Danish company has made a name for itself among pharmaceutical stocks on the strength of its diabetes and weight loss drugs Ozempic and Wegovy.

Novo Nordisk isn't exactly a new kid on the block, but with the advent of semaglutide, the ingredient behind both treatments, the company's revenue has increased sharply. Earnings are expected to grow 42% this year and 20% next year.

Institutional investors are taking note and, as always, are mainly responsible for the stock's rise. About 80% of a stock's price movement is attributable to big institutions. MarketBeat's Novo Nordisk institutional ownership data show 1,132 institutional buyers accounted for $8.49 billion in inflows in the past 12 months, versus 545 responsible for only $860.63 million in outflows.

Novo Nordisk stock gapped out of a flat base on November 24 and remains in buy range as it's just 1.4% above the buy point of $104.