The Nairobi Securities Exchange Ltd All Share Index (^NASI) was introduced as an alternative index in 2008, with a base value of 100 as of January 2008. It is a market cap weighted index consisting of all the securities on the NSE. Its measure and attention is therefore on the overall market capitalization rather than the price movements of select counters. Prices are based on last trade information from NSE’s Automated Trading System.