An oscillator is any object or data that moves back and forth between two points. In other words, it’s an item that is going to always fall somewhere between point A and point B. Think of when you hit the oscillating switch on your electric fan.
Think of our technical indicators as either being “on” or “off”. More specifically, an oscillator will usually signal “buy” or “sell”, with the only exception being instances when the oscillator is not clearly at either end of the buy/sell range.
Does this sound familiar? It should! Stochastics, Parabolic SAR, and the Relative Strength Index (RSI) are all oscillators. Each of these indicators is designed to signal a possible reversal, where the previous trend has run its course and the price is ready to change direction.
Let’s take a look at a few examples.
On the 1-hour chart of USD/EUR below, we have added a Parabolic SAR indicator, as well as an RSI and Stochastic oscillator. As you have already learned, when the Stochastic and RSI begin to leave their “oversold” region that is a buy signal.
Here we get buy signals between the hours 3:00 am EST and 7:00 am EST on 08/24/05. All three of these buy signals occurred within one or two hours of each other, and this would have been a good trade.
We also got a sell signal from all three indicators between the hours of 2:00 am EST and 5:00 am EST on 08/25/05. As you can see, the Stochastic indicator remained in the overbought for a pretty long time - about 20 hours. Usually when an oscillator remains in the overbought or oversold levels for a long period of time, that means there is a strong trend occurring. In this example, since Stochastic stayed overbought, you see there was a strong uptrend present.
Now let’s take a look at the same leading oscillators messing up, just so you know these signals aren’t perfect. Looking at the chart below, you can quickly see that there were a lot of false buy signals popping up. You’ll see how one indicator says to buy, while the other one is still saying sell.
Around 1 am EST on 08/16/05, both RSI and Stochastic gave buy signals, while Parabolic SAR still showed a sell signal. Yes, Parabolic SAR gave a buy signal 3 hours later at 4 am EST, but then Parabolic SAR turned into a sell signal one bar later. If you actually look at the bar with the Parabolic SAR below it, notice how it’s a strong looking red bar with very short shadows. Also, notice how the next bar closed below it. This would not have been a good long trade.
On the last two oversold (buy) signals given by Stochastic, notice how there is no indicator at all for RSI, but Parabolic SAR is giving sell signals. What’s going on here? They are each giving you different signals!
What happened to such a good set of indicators?
The answer lies in the method of calculation for each one. Stochastic is based on the high-to-low range of the time period (in this case, it’s hourly), yet doesn’t account for changes from one hour to the next. The Relative Strength Index (RSI) uses change from one closing price to the next. And Parabolic SAR has its own unique calculations that can further cause conflict.
That’s the nature of oscillators – they assume that a particular chart pattern always results in the same reversal. Of course, that’s hogwash.
While being aware of why a leading indicator may be in error, there’s no way to avoid them. If you’re getting mixed signals, you’re better off doing nothing than taking a ‘best guess’. If a chart doesn’t meet all your criteria, don’t force the trade! Move on to the next one that does meet your criteria.