The index is calculated as a correlation between the sum of the market capitalizations of its component companies on the given day (corrected for free-float) and the sum of the market capitalizations of the companies (corrected for free-float) on the previous day.

The market capitalization is the product of the number of issued shares multiplied by the the price of the last transaction with the stock for the day.

The index calculation started on 20 October 2000 at a base level of 100 points, which means SOFIX is now seven years old.

The index has had 7 first days of a new year so far and, whether an accident or a tendency, it ended 5 of these with declines. The drop was smallest on the first business day of 2001 (0.12%), while the greatest decline was registered yesterday – 1.72%.

The only two advances on a first business day for a calendar year were recorded in 2007 and 2002 – 1.6% and 0.06%, respectively.

We should also note that SOFIX added 11.15% in 2001, and 57% in 2002. The highest annual advance so far has been in 2003 – 135%.

In the period 2004 – 2007 Bulgaria's blue chip indicators rose between 32% and 48% annually.

DateChangeLevelGrowth y/y2 Jan 2001-0.12%106.6111.15%2 Jan 20020.06%118.757.62%2 Jan 2003-0.85%181.52135.11%2 Jan 2004-1.41%447.9337.63%3 Jan 2005-0.28%623.5932.02%3 Jan 2006-0.31%822.9748.28%3 Jan 20071.60%1243.7344.42%2 Jan 2008-1.72%1737.42