On real monthly charts, what did an “overbought” reading tell you?

It didn't reliably predict a fall

Momentum and the RSI

Some moves are strong; others are running out of steam. The RSI (Relative Strength Index) scores recent momentum from 0 to 100.
It compares the size of recent up-moves with recent down-moves, usually over the last 14 candles. Mostly gains: high RSI. Mostly losses: low RSI.
Above 70 is called overbought: buyers have been pushing hard. Below 30 is oversold: sellers have been pushing hard.
On real monthly charts, an “overbought” reading was followed by a fall only about 48% of the time. Basically a coin flip.
Common mistake
Mistake: “RSI is over 70, so it must fall.” In strong trends RSI can stay overbought for months while price keeps climbing.
Key takeaway
RSI measures strength, not what comes next. Use it as one clue, never as a signal on its own.

RSI usually looks at the last... 14 candlesIts creator, J. Welles Wilder, used 14 periods, and that's still the standard setting.
RSI above 70 is called... OverboughtAbove 70, recent gains have been much bigger than recent losses.
On real monthly charts, what did an “overbought” reading tell you? It didn't reliably predict a fallA fall followed only about 48% of the time: no better than a coin flip.
RSI stays above 70 for weeks while price keeps climbing. This shows... Strong buying momentumHigh RSI measures strength. Strong trends can keep it high for a long time.