Early morning today, the BSE Sensex, India’s most popular stock market index crossed 50,000 points during intra day trading.
Not surprisingly, this led to the bubbly being opened on the social media and business TV. These are celebrations which will be carried into the newspapers appearing tomorrow morning. This is hardly surprising given that every time the Sensex has crossed one of these major landmarks, the media has gone crazy celebrating it.
And I don’t have a problem with it, given that the media is in the business of cashing in on good sentiment or to put it more precisely, creating good sentiment and then cashing in on it. The days of what bleeds that leads, are long gone.
One of the ways of celebrating is through graphics and data. One such graphic was shared by the Twitter handle of Business Today. It basically plots the number of days the Sensex has taken over the years to move 10,000 points in the upward direction.
Hence, it plots the number of days, the Sensex took to cross the first 10,000 points, then move from 10,000 points to cross 20,000 points and so on, and finally, to move from 40,000 points to cross 50,000 points.
This is how it looks like.
Looking at the above chart, Business Today concludes that the Sensex moving from 40,000 points to crossing 50,000 points has been the fastest, as it has happened in just 415 days. This, as we can see, is the least number of days. The next fastest was between 10,000 points and crossing 20,000 points, which took 432 days, which is seventeen days more.
Yay, and that is a cause for huge celebration. Okay, Business Today, didn’t say that, I added it.
During the course of my nearly 18 years of writing for the business media, I have seen a lot of stupid charts and data being used to make a point, but this takes the cake.
Why? Simply because it doesn’t take fifth standard percentages into account.
The BSE Sensex is an index. Every index has a base value. The base value of the BSE Sensex is 100. So, when the BSE Sensex first rose from 100 points to 10,000 points in 5,942 days, it meant a rise of 9,900 points or 99 times the original value of 100 or 9900%.
In comparison, the rise between 40,000 points and 50,000 points is just 25%. So, what are we really comparing? Who are the editors clearing such graphics? Why are people being misled on such simple data points?
The question is how do we analyse this properly. The right way to do this is look at the average jump in percentage terms per trading session, in each bracket. So how do we calculate this? The Sensex moved up 9,900% in 5,942 sessions, when it crossed the first 10,000 points. Hence, it moved around 1.67% per trading session on an average (9,900% divided by 5,942 trading sessions), during the period .
Further, the Sensex moved 25% in 415 sessions, when it moved from 40,000 points to cross 50,000 points. Hence, it moved 0.06% on average per trading day (25% divided by 415 trading sessions), during the period. So, the movement of the Sensex between 40,000 points to crossing 50,000 points has been much slower than crossing the first 10,000 points.
Here is how the proper chart looks like.
What does this tell us? It tells us that the first 10,000 points were achieved the fastest. This was followed by the movement between 10,000 points and 20,000 points, where the average gain was 0.23% per trading session. The movement between 40,000 points and 50,000 points at 0.06% per trading session comes third.
Sorry for belabouring on this rather basic point but I get really irritated when people use mathematics and data to mislead, sometimes not even knowing that they are misleading.