Does an RSI Above 70 Mean a Stock or Index Is About to Fall?

RSI is one of the first indicators most traders put on a chart, and one of the most misused. The usual rule, "above 70 sell, below 30 buy", sounds simple. The data show why it is not that simple.

What people on X are asking

In February 2026 one account posted a beginner thread asking what RSI is, describing above 70 as possibly overbought and below 30 as possibly oversold. In April 2026 a reply asked how to use RSI and stochastic RSI together, and in May another trader asked how to use RSI to decide whether to go long or short. Here is how it works and what a test on the S&P 500 shows.

The fact-checked answer

How RSI is calculated. Wilder's RSI takes the average gain and the average loss over a period (14 by default), using his smoothing method, and turns their ratio into a number between 0 and 100: RSI = 100 − 100 ÷ (1 + average gain ÷ average loss). If prices only rose, RSI would be 100; if they only fell, 0. StockCharts' ChartSchool explains that readings above 70 generally indicate overbought conditions and below 30 oversold, and that RSI also generates signals through divergences, failure swings and centreline crossovers.

UXS chart

S&P 500 14-day RSI (daily)

RSI (14, Wilder smoothing): latest

33.49

November 5, 2026

Highest in chart period

86.69

January 26, 2018

Lowest in chart period

17.66

October 11, 2018

Change over 1 year

-39.5%

vs November 5, 2025

Source: FRED, Federal Reserve Bank of St. Louis (FRED SP500). Retrieved November 10, 2026. Chart computed and drawn by UXS from the raw series. Computed by UXS from the FRED S&P 500 daily close (price index, no dividends). Levels of 70 and 30 are the traditional overbought and oversold lines. Download the data (CSV)

Last 12 months

Month-end values (World Bank: monthly averages). Tap a column header to sort.

Month	RSI (14, Wilder smoothing)
2026-11	33.49
2026-10	40.11
2026-09	48.12
2026-08	53.52
2026-07	52.77
2026-06	55.99
2026-05	73.53
2026-04	70.21
2026-03	42.63
2026-02	48.38
2026-01	53.36
2025-12	51.03

What overbought really means. RSI above 70 means gains have heavily outweighed losses recently. That describes momentum, not value. Strong markets push RSI above 70 and keep it there; the S&P 500's RSI was above 70 on 252 of about 2,500 trading days since late 2016, about 10% of the time, and much less often below 30 (41 days). In 2026 it peaked at 77.7 on May 14 and dropped to 27.7 on March 30. On the latest reading in early November it was 33.5, near oversold after the index's fall from its October high.

What happened one month (21 trading days) later, S&P 500 since late 2016

Computed by UXS from FRED SP500 daily closes. Price-only returns, no costs. Overlapping periods and a strongly rising decade mean these are descriptive, not a tested strategy. Tap a column header to sort.

Signal	Cases	Average 1-month change	Share higher
All days	about 2,480	+1.17%	69%
RSI crosses above 70	68	+1.30%	72%
RSI crosses below 30	22	+2.58%	73%

What the test shows. On the S&P 500 since late 2016, crossing above 70 was not a reliable sell signal: the index was higher a month later slightly more often than on a random day. Crossing below 30 was followed by above-average gains, but only 22 times, which is too few to rely on, and a decade of rising prices helps any buy-the-dip rule. In a long bear market, oversold readings can keep getting more oversold. See what a bear market is.

How traders actually use RSI.

• Trend filter: ChartSchool cites analyst Constance Brown's observation that in bull markets RSI tends to fluctuate between 40 and 90, with the 40–50 zone acting as support. Pullbacks to that zone in an uptrend are watched as entries.
• Divergence: price makes a new high but RSI makes a lower high, a sign momentum is fading. ChartSchool warns that divergences are misleading in strong trends: a strong uptrend can show numerous bearish divergences before a top.
• Combining with levels: RSI is more useful together with support and resistance, moving averages or volume. See how to use the 200-day moving average.
• Stochastic RSI: applies the stochastic formula to RSI itself, so it is faster and noisier. Using both mainly doubles the same information.

Long or short? The May 2026 question has no indicator answer. RSI can tell you whether momentum is stretched, but whether to go long or short depends on your trend view, your entry and your stop. Pair it with sound stop-loss placement and a tested plan.

Another popular momentum signal is tested in what a MACD crossover means and whether it is reliable.

Price levels are another common reversal tool; see why broken support often turns into resistance.

Decision helper

Common mistakes

• Selling just because RSI is above 70.
• Ignoring the trend and timeframe.
• Changing the period until it fits past data.
• Using RSI and stochastic RSI as if they were independent confirmations.

FAQ

What is RSI in trading?

A 0–100 momentum indicator comparing recent average gains with average losses.

What does RSI above 70 mean?

Overbought: gains have dominated recently. It is not a sell signal on its own.

What does RSI below 30 mean?

Oversold: losses have dominated. Prices can keep falling.

What is the best RSI setting?

14 periods is standard; shorter settings are faster and noisier.

Does RSI work?

As context, yes; as a stand-alone buy or sell rule, our S&P 500 test found little edge.

What is RSI divergence?

When price makes a new high or low but RSI does not confirm it.