The BSE mid-cap index closed at a 52-week low of 5,856.61 on Tuesday as scrips continued to see heavy selling pressure from foreign institutional investors (FIIs). This,on a day the benchmark index Sensex gained marginally. Overall,the mid-cap index has lost more than 17% this calendar year compared with Sensexs fall of 4%. Future Retail is the biggest mid-cap loser in the current calendar year,with a decline of 65%. Muthoot Finance has lost about 50% in CY13,while Apollo Tyres has lost nearly 35%. Other prominent losers include Gitanjali Gems (25%),Kayur Vysya Bank (25%),Vijaya Bank (31%) and Jet Airways (23%). * BSE Sensex * NSE Nifty With FIIs selling more than $1.5 billion in equities this month,mid-caps have been facing the heat. According to data sourced from Capitaline, companies with higher FII holding of more than 15% have seen their shares lose more than 15% in average year-to-date returns. The slide in companies with lower FII holdings has been a little over 8%. While FIIs have been largely wary of the mid-cap space,they have shown interest in quality stocks. FIIs have been very careful in their selection. They have not ventured beyond the top-200 stocks, said AK Prabhakar,senior vice-president (equity),Anand Rathi Securities. Standard Chartered,in its research note on Tuesday,said that FII shareholding in the small- and mid-cap stocks are at an all-time high. The note added that the liquidity among the small- and mid-caps tends to contract when the markets are under pressure. According to analysts,a spurt in margin calls among mid-cap stocks has also contributed to their undoing. Some operators have been under pressure due to the commodity and currency market trends. For instance,Tata Coffee share has seen a huge correction as a result of margin-calls, an analyst said on condition of anonymity. The stock has shed more than 30% this month. Analysts reckon mid caps could see pressure on their earnings going forward owing to their sizeable exposure to foreign currency debt. Huge debt,corporate governance issues and lack of promoter backing remain major concerns for the mid-cap investor, said Anand Bagaria,research analyst,Finquest Securities. * Best Performing Mutual Funds