Bringing Data Science to Nifty Analysis. A small 🧵

As per Normal Distribution 68% of the time movement is with 1% SD Limits.

For 95% pf the times movement is within 2% SD limits.

And its only 0.3% of the times that movement exceeds 3 SD.

Since 95% covers a lot of ground that's why 2SD is considered to be a a safe range for most events.

The farther we move from the average, chances of occurrence go down. This is what Taleb sahab calls Tail risk, because it lies in the tail of the standard distribution curve.
Normal distribution occurs everywhere. See this example

https://t.co/HHwUpIXTRG
Bollinger Band, which is a very popular indicator has a setting of 2SD. Because its expected that 95% of the time moves will be confined to 2SD limits.

When we say that price is at upper/lower Bollinger band, we are saying that it has reached 2 SD limits and likely to reverse.
Now coming to current scenario, open Nifty daily chart and apply two bollinger Bands on it.

First with default setting and in second change settings to 3 standard deviation.

Crossing 3 SD boundary means that Nifty is now in very rare territory where it has been only 0.3%
I have plotted a chart and you can see that wherever nifty has approached 3SD range it has taken a bounce.

Right now Nifty is not at 3SD levels (Looks like around 2.5 SD levels).

Note: some important points to remember and another chart in next tweet.
Important Points !

1. Nifty crossing 3SD is not impossible its just that there is only 0.3% probability of this tail risk.

2. The moves are considered from average (mean µ to be precise). Hence they are not absolute and are on a rolling basis. See the chart of March'20 fall.

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Legacy site *downloads* ~630 KB CSS per theme and writing direction.

6,769 rules
9,252 selectors
16.7k declarations
3,370 unique declarations
44 media queries
36 unique colors
50 unique background colors
46 unique font sizes
39 unique z-indices

https://t.co/qyl4Bt1i5x


PWA *incrementally generates* ~30 KB CSS that handles all themes and writing directions.

735 rules
740 selectors
757 declarations
730 unique declarations
0 media queries
11 unique colors
32 unique background colors
15 unique font sizes
7 unique z-indices

https://t.co/w7oNG5KUkJ


The legacy site's CSS is what happens when hundreds of people directly write CSS over many years. Specificity wars, redundancy, a house of cards that can't be fixed. The result is extremely inefficient and error-prone styling that punishes users and developers.

The PWA's CSS is generated on-demand by a JS framework that manages styles and outputs "atomic CSS". The framework can enforce strict constraints and perform optimisations, which is why the CSS is so much smaller and safer. Style conflicts and unbounded CSS growth are avoided.