In the span of about three months, the Tehran Stock Exchange’s benchmark index has surged almost 23 percent, setting new records that officials argue are clear indications that Iran’s economy is far from hurting despite international sanctions.

But behind the number, analysts and economists say, is a closed-door system in which a handful of companies are influencing the market.

While many concede the months long rally is fueled by increased liquidity and the government’s push to privatize a number of public sector firms by next year, the real question is how sustainable that rally is and on what it is based.

“This is not the real index of the market in Iran,” said economist Saeed Leilaz, who like many other analysts believes the gains are largely the result of planned trades between government-related bodies rather than demand by ordinary investors. “If you pull quasi-governmental firms out of the market, it drops remarkably.”