NISM-Series-XV: Research Analyst · Technical Analysis

Momentum Oscillators and Volume Indicators for NISM Research Analyst

Updated 11 October 2026 · Fact-checked

Momentum oscillators such as RSI, stochastic and rate of change measure the speed of price moves and flag overbought or oversold zones. Volume indicators such as OBV and open interest test whether participation confirms the price trend. You solve questions by applying the formula or reading the signal rule.

Understand Momentum Oscillators and Volume Indicators

A momentum oscillator measures how fast price is changing, not where it is. It moves within a range or around a centre line. This helps you judge whether a trend is strong, tiring or stretched.

RSI (Relative Strength Index) compares average gains with average losses over a period, usually 14. It moves between 0 and 100. By the usual convention, above 70 is overbought and below 30 is oversold. In a strong trend, RSI can stay overbought or oversold for a long time. So these levels are warnings, not automatic sell or buy orders.

The stochastic oscillator compares today's close with the recent high-low range. The idea: in an uptrend, closes tend to be near the high of the range. In a downtrend, they tend to be near the low. It has two lines, %K and %D, where %D is a moving average of %K. It also runs from 0 to 100. Common levels are 80 (overbought) and 20 (oversold). RSI uses average gains and losses. Stochastic uses the close's position in the range.

Rate of change (ROC) compares today's price with the price n periods ago. It is a percentage. It swings above and below a zero line. Above zero means price is higher than n periods ago. Below zero means lower.

Volume shows how many shares traded. A move on rising volume is more convincing than one on falling volume. On-balance volume (OBV) is a running total. You add the day's volume when the close is higher than the previous close. You subtract it when the close is lower. You leave it unchanged when the close is equal. Open interest is the number of outstanding derivative contracts not yet closed. Rising price with rising open interest suggests new money supports the trend. Divergence between price and any of these indicators is an early warning of a possible reversal.

Key formulas to remember

RSI: RSI = 100 − [100 ÷ (1 + RS)]; RS = average gain ÷ average loss over the period (usually 14). Range 0 to 100. Above 70 overbought, below 30 oversold by convention.
Stochastic %K: %K = (Close − Lowest low) ÷ (Highest high − Lowest low) × 100; Lowest low and highest high are over the look-back period (commonly 14). Overbought above 80, oversold below 20 by convention.
Stochastic %D: %D = moving average of %K (commonly 3 periods); The signal line. A %K crossing %D is read as a signal.
Rate of change: ROC = [(Current close − Close n periods ago) ÷ Close n periods ago] × 100; Zero line is the centre. Positive means price is above its level n periods ago.
On-balance volume: OBV today = OBV yesterday + volume (close up); − volume (close down); + 0 (close unchanged); Only the direction of the close matters. The full day's volume is added or subtracted.
Open interest and price reading: Price up + OI up = strong; Price up + OI down = weak (short covering); Price down + OI up = weak market; Price down + OI down = downtrend losing strength; A common textbook reading. Rising OI means new positions are being added.

How to solve Momentum Oscillators and Volume Indicators questions

Use this order for any question on oscillators or volume indicators.

1Identify the indicator named in the question: RSI, stochastic, ROC, volume, OBV or open interest.
2Decide whether it is a calculation or an interpretation question.
3For a calculation, write the formula and substitute the numbers carefully. Keep the order of terms as in the formula.
4For interpretation, recall the standard levels: 70/30 for RSI, 80/20 for stochastic, zero line for ROC.
5Check for divergence: price makes a new high or low but the indicator does not.
6Check whether volume or open interest confirms the price move.
7Eliminate options that call a level a certain signal or use the wrong direction, then pick the best match.

Quickest way: Level and direction shortcut

When to use it: Use this for interpretation MCQs when time is short.

Locate the indicator's zone: above 70 or 80 means stretched up, below 30 or 20 means stretched down.
Ask whether price and indicator agree. If they disagree, it is divergence and a warning.
For OBV, only the sign of the price change decides add or subtract.
For open interest, rising OI means new money and a stronger trend.
Reject options with words like always or guaranteed.

Common mistakes in Momentum Oscillators and Volume Indicators

Treating RSI above 70 as an automatic sell signal.
The textbook labels it overbought, so it sounds like a command.
Fix: Remember that in strong trends RSI can stay high. It is a warning that needs confirmation.
Mixing up the RSI levels (70/30) with stochastic levels (80/20).
Both are 0 to 100 oscillators with similar zones.
Fix: Learn the pairs: RSI 70/30, stochastic 80/20.
Using the close minus the highest high in the numerator of %K.
The range appears in both numerator and denominator, so terms get swapped.
Fix: Numerator is close minus lowest low. Denominator is highest high minus lowest low.
Adding only part of the volume in OBV, or adding volume on an unchanged close.
Students think OBV scales with the size of the price move.
Fix: Add or subtract the whole day's volume. If the close is unchanged, change nothing.
Reading rising price with falling open interest as strong.
Price rise alone looks bullish.
Fix: Falling OI means positions are closing, often short covering. The rally is weak.
Dividing by the new price in ROC.
Students divide by the latest value by habit.
Fix: Divide by the price n periods ago.

Worked examples

Example 1

A stock's highest high in the last 14 days is ₹250 and lowest low is ₹200. Today's close is ₹235. Find the stochastic %K and say what it indicates.

Show the solution

Numerator = Close − Lowest low = 235 − 200 = 35.
Denominator = Highest high − Lowest low = 250 − 200 = 50.
%K = 35 ÷ 50 × 100 = 70.
70 is between 20 and 80, so it is neither overbought nor oversold by the usual levels.

Answer: %K = 70. It is in the neutral zone, closing in the upper part of the range.

Example 2

OBV is 50,000 at the end of Day 1. Day 2: close higher, volume 12,000. Day 3: close lower, volume 20,000. Day 4: close unchanged, volume 8,000. Find OBV at the end of Day 4.

Show the solution

Day 2: close higher, so OBV = 50,000 + 12,000 = 62,000.
Day 3: close lower, so OBV = 62,000 − 20,000 = 42,000.
Day 4: close unchanged, so OBV stays at 42,000.

Answer: OBV at the end of Day 4 is 42,000.

Exam tips

Memorise the zones: RSI 70/30, stochastic 80/20, ROC zero line.
Expect direct calculation questions on %K, ROC and OBV. Practise each once by hand.
Watch for options that say an oscillator signal is certain. They are usually wrong.
For open interest questions, combine the price direction with the OI direction before choosing.
Divergence questions: price new high with indicator lower high is a bearish warning.

Practice questions from Technical Analysis

Momentum Oscillators and Volume Indicators: frequently asked questions

How do I calculate RSI for the exam?

Find RS as average gain divided by average loss over the period, usually 14. Then use RSI = 100 − 100 ÷ (1 + RS). If RS is 1, RSI is 50.

What is the difference between RSI and stochastic?

RSI compares average gains with average losses. Stochastic compares the close with the recent high-low range. RSI uses 70/30 levels and stochastic uses 80/20 by convention.

How do you use on-balance volume?

OBV is a running total of volume, added on up-close days and subtracted on down-close days. You compare its direction with price. If OBV rises while price is flat or rising, volume supports the move. A divergence is a warning.

Does overbought mean the price will fall?

No. It means the price has risen quickly and may be stretched. In strong uptrends, an oscillator can stay overbought for long, so you look for confirmation.