$$ What is Overbought & Oversold?

Hint: It's not RSI 70 and 30. In fact, an RSI tag of 70 or 30 is meaningless.

John Bollinger wrote at p. 170 of Bollinger on Bollinger Bands that during uptrends, the 14-day RSI oscillates between 80 and 40 while during downtrends RSI(14) ranges between 60 and 20.

Constance Brown explored these RSI(14) range rules more in depth in Chapter 1 of her book Technical Analysis for the Trading Professional.

Both Bollinger and Brown cite Andrew Cardwell's work on the RSI. Andrew has not published, but Steven Vincent of BullBear recently interviewed Andrew for an hour at the June Trader Expo in LA. The interview is broken into six 10 minute segments on YouTube. Here is Part 1 of 6 of the interview. You'll find Parts 2-6 at YouTube.