Properties And Spectral Interaction Of Zero-Lag FiltersIntroduction
In this post i want to talk about zero-lag filters, how they interact with the price and its frequency components. I'll also talk about the phase-response, and try to clearly explain how it works and what information it can give to the user. I'll finally introduce the concept of forward-backward filtering as well as zero-phase non stable causal smoothing.
Filters And Lag
Lag is a term used in technical analysis that refer to the phase-shift induced by filters. As you know filters interact with the frequency content of a signal, they can remove certain frequency components or amplify/reduce their amplitude. Lag can be perceived when smoothing market price by using a low-pass/band-pass filter, in short a filter with lag will return past-trends instead of new one, this can be considered a tradeoff where the user can access information easier to interpret at the cost of reactivity.
Phase Response
One can visualize the phase of filters thanks to the phase-response. The phase-response is a value expressed in degree or radians and is described as the relationship of a sinusoid and the phase, its a bit confusing so let me explain you how it works. Remember that a sine wave have a amplitude and a frequency and a period, she can also have a certain phase expressed in degree, for example in this image www.davidbridgen.com the sine wave in red is shifted by 180 degree, the phase response of a filter will tell you how many degree a frequency component (sinusoid) is shifted after being filtered.
Here an image showing a frequency response : i.stack.imgur.com
This is because frequency components are shifted that lag can be perceived.
Tackling The Lag Problem
So technical analyst tackled this problem by making zero-lag filters, of course the term zero-lag must be taken lightly, basically zero-lag will mean a filter who better fit to the data. So how do this work ?
Remember that a filter posses a frequency response, the frequency response tell you how the filter interact with the frequency components of the signal. So with most of the zero-lag filters lag will be reduced by amplifying some frequency components of the filter, some zero-lag filters will have the following frequency response :
This frequency response amplify certain frequencies before the transition band, this allow the filter to better fit to the signal. Of course this is not the only way to make filter have zero-lag, common zero-lag filter structures include :
amplifying certain frequencies in price -> applying filter
applying a bandpass filter to the price -> summing the result with a low-pass filter
multiply a low-pass filter with cutoff frequency a by 2 -> subtract the result to a low-pass filter of cutoff frequency b with a > b
As you can see such filters produces better fit but are less smooth than other filters of the same period, this is logical, you are amplifying certain frequencies, and some of those frequencies can be high ones, basically noise, which explain the reactivity-smoothness tradeoff. The amplification process also creates artifacts such as over/undershoots which are direct effects of amplification.
Zero-Phase Smooth Filters - Non Causal
Any filter can have literally zero-lag and be smooth by a method called forward-backward filtering, this method consist in filtering the data from the left to the right and then filtering this result from the right to the left, during the last step you basically shift back the filtered result to the right, which compensate the shift produced by the first step filtering.
Such filters work by reversing the orders of the signal samples, now they are said to be non-causal because they no longer use only past information, this is why such filters are used offline , their phase response is equal to 0. Those filters are the core of many repainting indicators.
Zero-Phase Smooth Filters - Causal
Impossible ? In theory yes, at least with FIR filters, however IIR filters can work differently. IIR filters are less stable than FIR filters and posses a non-linear phase , this mean that their phase is not a linear function. IIR filters are filters using past outputs as input, as said they can sometimes produce zero-lag smooth outputs, but those results are not stable and does not occur every time, in facts they are rare events.
An example is made by using double exponential smoothing
Using low values for beta can produce non-stables results appearing non-causal, and sometimes even great fits.
However those effects does not appear constantly. Another way to have causal zero-lag filters is to forecast the data and smooth it, however you then are affected by the accuracy of your forecast model, how unfortunate.
Conclusion
This post took more time than necessary, but it is interesting to see how zero-lag filters works from a signal-processing point of view. So from now on if you see filters appearing to good to be true, you are certainly dealing with one using forward-backward filtering, either way you can't violate causality, no matter how hard you try...its also socially inappropriate (lame jokes !!!!!) .
Thanks for reading !
Phase-1
PhaseBio technical studyThere is a strong support area around $9.5 - $10.5
Could be a good opportunity if it keeps respecting the limits.
Technical data
RSI @42 (waiting for this indicator to go higher)
OBV reaching for higher highs
Bollinger bandwith relatively high.
Not buying yet, but it's worth it to keep on your watchlist.
POTENTIAL XAUUSD BUY/Long Position- Change in direction
- Bullish Movement Anticipated
- Price Floatation below previous support (expectation of breakthrough - resistance)
- Candlestick closure as bearish candlestick - expecting stoploss hunting before breakthrough resistance
- USD news manipulated results (remember news creates volatility not change of market direction)
URA | Better ROI with less risk than gold and silverWhy buy gold and silver at premium while them still being in a bear market, when you can buy uranium cheap at accumulation levels. Does it really make sense to buy silver > $10 and gold > $1000 at given prices vs the risk it carries for downside potential vs a strong base near bottom that has lots of upside potential at lower risk. Speaking common sense. Adding to portfolio.
Bitcoin Daily Update (day 232)I believe that it is possible to beat the market through a consistent and unemotional approach. This is primarily achieved through preparing instead of reacting. Click here to learn more about how I use the indicators below and Click here to get my complete trading strategy! Please be advised that I swing trade and will often hold onto a position for > 1 month. What you do with your $ is your business, what I do with my $ is my business.
I recently posted Bitcoin Bubble Comparison - 3 Day Chart . It provided new dates and prices for the bottom, however it’s still slightly too early to abandon my predictions from the previous Bitcoin Bubble Comparison ]Bitcoin Bubble Comparison: 1 day - 5 days = < $5,750 | bottom prediction: $2,860 by 10/30 | | Calling for $35 ETH around the same time
Previous analysis / position: Left a comment on October 18th’s post saying that I wouldn’t be able to do the daily update and that I was watching the 4h TD Sequential and Stochastic. Still felt good about short positions due to $6,400 holding as strong resistance / Short BTC:USD from $6,367 | Short USDT:USD from $0.968
Patterns: Descending triangle / hyperwave
Horizontal support and resistance: S: $6,400 | R: $6,428
BTCUSDSHORTS: Appear to have created a lower high without re tested top of triangle
Funding Rates: Longs pay shorts 0.01%
Short term trend (4 day MA): Broke through 4 but now pulling back below. Wait to see where it closes before considering it bullish
Medium term trend (4 week MA): Bear
Long term trend ( 32 Week): Bear
Overall trend: Bear
Volume: Last few days have been well below MA
FIB’s: 0.618 = $6,530 | 0.5 = $6,441 | 0.382 = $6,351
Candlestick analysis: Bearish spinning tops, today forming bullish spinning top
Ichimoku Cloud: Fell out of 4h cloud, but still has not gotten kumo twist or bearish TK Cross. 1h cloud shows a lot of resistance from $6,400 - $6,480
TD’ Sequential: 4h: G3 | 12h price flip
Visible Range: Showing strong resistance from $6,400 - $6,800
Price action: 24h: +0.57% | 2w: -2.72% | 1m: +0.5%
Bollinger Bands: Continuing to resist daily MA
Trendline: Top of descending triangle = $6,670 | Phase 2 hyperwave = $6,000
Daily Trend: Chop
Fractals: Up: $6,792 | Down: $6,057
RSI: Hanging around 50 on all time frames
Stochastic: 4h starting to rally after calling a good buy. Daily is recrossing bearish after a double top
Summary: I entered based on the 12h red 2 below the red 1 in combination with the button top. Based on that entry I should be setting the stop loss above the 12h red 1 at ~$6,501. That is only 2% risk and there really isn’t reason to set it tighter than that.
After taking a number of losses I start to second guess my entries and stop losses. Sometimes I have an inclination to tighten the stops due to be afraid of losing and other times I have a tendency to really widen them due to being frustrating from getting whipsawed.
The last couple weeks have been a lot of the former. Instead of using the stop loss that the TD’ Sequential trading system outlines, I used an approach from Wyckoff.
He states something along the lines of: “When there is a breakout / breakdown of a trading range and the price quickly returns to the middle of the range then it was likely a fakeout”
I entered on the $6,400 breakdown and figured that a return to > $6,450 would indicate a fake breakdown which usually precedes a strong rally. So I set my stops at $6,451 on BTC’ and $204.2 for ETH. Fortunately the BTC’ stop didn’t trigger, unfortunately the ETH’ stop did and there was not the follow through that I was expected. As it stands now I was stopped out on the very top on a 1h wick (which was a green 9).
Trading successfully long term is much more about losing than it is about winning. Prolonged losing streaks will challenge your motivation, confidence, sanity, and finances. Risk management is only one piece of the puzzle. The other part is emotional control, and I could argue that is even more important.
You can tediously manage risk 99% of the time, but that won’t matter if you let your emotions get the best of you on the other 1%.
I have found two very important ways to help control my emotions after taking a string of losses. First I shut off the computer and take a day off. I go outside, socialize and gain some perspective. Then I come back re charged and ready to get back in the trenches.
Another thing that really helps is not adding to losing positions. It can be very tempting to add at a better price when a position moves against you. Controlling that urge will help to minimize losses and maximize wins. Furthermore it will cause less stress/anxiety when things are going your way.
Set the stop loss then forget about it!
In regards to my USDT:USD position, I feel comfortable holding onto that as long as BTC’ is rallying. If it starts dumping then I will look to exit that position.
I went to a bbq last night and today I am playing in a golf tournament. By this time tomorrow I expect to feel fully reinvigorated.
New market period entered for BTC USDT (6 min vid)Just going over some observations about BTC USDT and the potential entrance into a new market cycle.
1. The compressing descending wedge from the bull run has reached an end point.
2. New geometric form emerging as the waves begin cycling out of the compression
3. No prediction, just ideas.
Wyckof Accumulation Schematic? My last chart was a complete disaster.
Even though I pinpointed where the last dip should stop, the bounce was disappointing.
Now, this looks like a classic Wyckoff Acc. Schematic, the only difference I see is the "Creek" not going all the way to the resistance levels.
If it does happen, we should expect a spring any time soon, with an increase in volume and an abrupt pump.
We shall see.
cmtassociation.org
Wyckoff accumulation and Phases UpdateThis is an update on this TA:
Description of the Wyckoff method can be found here: stockcharts.com
As I mentioned in the old TA, things are moving much faster than I anticipated and there is also a glaring mistake in the previous pattern.
This update uses price from Bitstamp instead of Bitfinex because the price history is longer and price actions are a lot smoother.
The pattern fits perfectly on price action, levels and volumes so far.
Reason for the update is the attention this has received and because I think we've reach A critical point, namely that we have started phase C.
The shakeout is well on it's way and the depth of the market is being tested for supply. Volume point to an exhaustion of the down trend.
VEN breakout imminentIf an external event doesn't cause additional downward pressure on the market, VEN is set to breakout in the coming days.
Formation of a symmetrical triangle, a BB squeeze and a rise in the DMI+ and ADX creates a favourable scenario for VEN.
Coupled with fundamental analysis (upcoming rebranding and current airdrop), positive movement is likely.
ETHUSD Opportunity knocks for next Bull PhaseETHUSD
A fabulous weekend has developed into a terrible week for
the Alts. This should create another fabulous buy opportunity
over the coming 12 to 24 hours...and potentially lead into
another good weekend ahead...if we can pick this up at lower
levels without getting stopped out in the process.
First support is nearby at 630 which if broken now should lead
to further weakness back to 557-551 range (a good short when
triggered). Ideally though, for bulls still wanting to get long
here, ETH will plunge even lower, to 512 and maybe, if lucky
right back down to the rising dynamic support at around 447
before bouncing strongly. It might not reach here, but we can
still place orders in market at a coiuple of points above 447
and see if it gets struck. The 488-481 range is the other range
to target as a potential antry zone for longs on any further
weakness but any stops will have to remain below the 440
mark to keep from being hit...if you can handle the potential
9% downside from 481 there is 100% upside from 447.
Look to buy over the next 24 hours, when the pips are really
screaming. Need a plan and the courage to execute. The
stage is set...let's see how close we can get to the bottom
before committing to next long from here.
Might be time to go Long again. I see us close to finishing a B wave (which looks like it was a double zig zag) from a larger ABC zig zag up to reach the top of a even larger Wedge.
Here are my ideas of where I see us on a larger timeframe:
If A=C, we could have a possible high of around 460/470, but I would rather wait to see how the waves (within this C) reveal themselves to get a more accurate target.
We also have bullish RSI divergence.
As an added bonus; the moon phase correlates with this as well:(www.moonconnection.com)