The blue-chip SOFIX index, which tracks the 15 most liquid shares on the Bulgarian Stock Exchange (BSE), closed 0.03% higher at 329.85 points after falling by 0.38% on Friday.
The broader BG40, which includes the 40 most traded shares, was down 0.48% to 123.28 points after losing 0.02% in the previous trading session.
Total turnover on the regulated market rose to 1.0 million levs ($661,000/511,000 euro) from 762,210 levs on Friday.
Six of the 13 SOFIX components which were traded on Monday advanced, five fell and two ended flat.
Hydraulic equipment manufacturer M+S Hydraulic [BUL:5MH] was the top SOFIX gainer, closing 5.51% higher at 6.87 levs as 100 shares changed hands.
Bulgarian Real Estate Fund [BUL:5BU] led the blue-chip decliners, closing 1.35% lower at 0.513 levs in a volume of 3,500 shares.
The BG-REIT index, which tracks the performance of real estate investment trusts, ended 1.3% lower at 78.98 points after falling by 0.3% on Friday.
The BG TotalReturn30, in which companies with a free float of at least 10% have equal weight, gained 0.73% to 252.41 points, following a 0.59% decrease in the previous trading session.
The CGIX Corporate Governance index, which includes companies strictly applying corporate governance principles, ended 0.21% higher at 74.98 points after rising by 0.55% on Friday.
(1 euro = 1.95583 Bulgarian levs)