Sirma and Shelly also lifted the BGBX40, which tracks the 40 most traded shares on the Sofia bourse, and the BGTR30, in which companies with a free float of at least 10% have equal weight. Both indices were further helped by diversified group Stara Planina Hold [BUL:SPH], which added 4.00% to 10.40 levs.
Overall, the BGBX40 advanced by 0.44% to 168.46 points, while the BGTR30 index climbed by 0.11% to 851.26 points.
In contrast, the BGREIT, which tracks seven real estate investment trusts, lost 0.19% to 190.16 points. The index was held back by a 0.93% tumble in Advance Terrafund REIT [BUL:ATER] to 3.20 levs.
The BEAMX index, which tracks the ten most highly capitalised growth companies, shed 0.23% to 103.27 points on the back of a 4.44% drop in cargo drone developer Dronamics' special purpose vehicle Dronamics Capital [BUL:DRON] to 2.58 levs.
Total turnover on the main market of the BSE more than trebled to 1.68 million levs ($918,154/858,967 euro) on Thursday from 521,096 levs on Wednesday.
Pharmaceuticals maker Sopharma [BUL:SFA] was the day's most liquid stock, having generated 153,764 levs from the trading of 25,801 shares. The company's shares closed 0.68% higher at 5.96 levs.
(1 euro = 1.95583 levs)