RSI bands as a one-day shift of reverse-engineered levels

A later overlay and an earlier inversion

The relative strength index is a bounded oscillator computed from ordered price observations over a defined lookback and commonly read against fixed high and low thresholds. RSI bands are price-level curves obtained by solving an RSI construction for the price that would place the oscillator at a chosen threshold. Reverse-engineered RSI is an inversion of the RSI formula that maps a chosen oscillator reading back into a price on the same sampling interval.

A later RSI-band overlay was described as matching an earlier reverse-engineered RSI construction that used the 30 and 70 level curves after those curves were shifted one day forward. A one-day forward shift is a one-bar displacement of inverted RSI level curves that yields a visually similar overlay with a one-interval lead.

Published code and remaining differences

Implementation code published with the later overlay was said to produce essentially the same indicators as earlier published code, aside from that one-day forward shift.

Any remaining numerical differences between the two implementations were characterized as very small and possibly due to calculation details.

Framing, reply, and attribution

The later presentation was criticized for being framed as a new idea rather than as reuse of a previously published reverse-engineered RSI formula.

An editorial reply stated that the later construction had been developed independently. The same reply said a reference to the earlier reverse-engineered RSI work would be attached to the archived edition of the later article.

The critique treated public reuse of indicator formulas as acceptable only when the prior research contribution is attributed.