On the Tehran Stock Exchange, two tickers can hand a shareholder two completely different experiences on the same day. One trades smoothly: there is a buyer and a seller at every moment, and the gap between the bid and the ask stays narrow. The other is dry: you place an order and nothing happens for hours. The institution meant to close that gap is called the market maker (بازارگردان), and its name recurs week after week in Codal filings and in the assembly calendar. Yet its exact role has rarely been explained to the retail shareholder.
According to Sahmino's events calendar, which lifts assembly invitations and assembly decisions from Codal (Iran's official corporate filings registry), 62 assemblies of dedicated market-making investment funds were logged between 22 Tir and 12 Mordad 1405 (13 July to 3 August 2026) alone, an average of close to three per working day. That volume of activity shows market making is not a marginal institution in Iran's capital market. And yet this much-repeated institution, contrary to a widespread belief, does not guarantee the price of your shares, and never made such a promise.
Background: the problem market making was built for
The underlying issue is liquidity: how quickly, and how close to a fair price, an asset converts into cash. In a market where only a handful of scattered orders exist for a ticker at any instant, those few orders can move the price several percent. The result is that the buyer pays more and the seller receives less, without any news, profit or loss having occurred at the company. That is the hidden cost of a shallow board. (For the underlying concept, Sahmino's lesson on what liquidity is and why selling a house differs from selling gold walks the same spectrum from bank deposits to housing.)
The regulatory answer to that problem was to define a role called the market maker: an entity that commits to placing orders on both sides of a ticker's board so the gap between the bid and the ask does not widen excessively and the share stays tradeable. Its commitment is a commitment to presence, not to price.
How the commitment works: volume, spread, resources
A market-making commitment is not unlimited. It is defined inside a specific framework, built from three parameters:
- Volume: the market maker must keep at least a set quantity of orders posted on each side. That floor is what creates the board's minimum depth.
- Spread: the permitted distance between the best bid and the best ask. The narrower this is defined, the lower the round-trip cost for a trader.
- Resources: the cash and the shares the market maker can put behind the commitment. Resources are the real ceiling: the commitment only means something as far as the resources behind it reach.
Once that ceiling is filled, the market maker's presence effectively fades. The moment that happens, the board's depth thins quickly, and the same ticker that traded smoothly yesterday moves several percent today on thin volume. That thinning shows up in the order book, not in the price chart.
The numbers: Bank Mellat's board on Monday, 3 August 2026
The clearest recent case is the session of Monday, 3 August 2026 (12 Mordad 1405) in Vabmellat, the Tehran-listed ticker of Bank Mellat. That day the opening trade, the session low, the session high and the closing price were all one number: 1,199 rials. That figure is not a coincidence; it was exactly the top of the permitted daily price band for that session.
| Measure | Value (Monday, 3 August 2026) |
|---|
| Open, low, high and close | 1,199 rials (all four identical) |
| Permitted band that day | 1,131 to 1,199 rials |
| Previous close | 1,165 rials |
| Day change | 34 rials (2.92%) |
| Order book, buy side | 2,107 orders for 1,138,716,770 shares at 1,199 rials |
| Order book, sell side | all five rows empty |
| Traded volume | 5,179,357,680 shares across 10,418 trades |
| Traded value | 6,210 billion rials (about 621 billion tomans) |
| Net retail buying | 3,179,081,014 shares |
| Buyer strength | 1.26 |
The board figures come from the Tehran exchange's own official trading system and from Sahmino's own price series, and the two agree. Sahmino covered the mechanics of this same session earlier in Bank Mellat traded all session at a single price of 1,199 rials. How the daily band itself works is covered in Tehran Stock Exchange 101.
When the ceiling fills: what a buy queue actually means
Now read that same board through the market-making lens. The buy side held more than 1.1 billion shares of stacked orders. The sell side, across all five visible rows, was empty. In other words, by the end of that session there was no sell order left on the board at all.
In that state, neither the market maker nor any other institution can tell a fresh buyer that shares will reach them. If the market maker wanted to fill the sell side, it would have to sell shares it already holds at the top of the band, and its inventory of shares, like its cash, is limited and defined in advance. Once those resources run out, the commitment effectively ends and the board becomes what it is: one-sided.
The important point is that this one-sidedness happens in exactly the same way on sell-queue days, only in the opposite direction. That the direction on 3 August happened to be positive changes nothing in the mechanism.
What a market maker does not guarantee
This is where the most common misreading sits, and the distinction is simple:
- It does guarantee: that within the defined volume, spread and resources, there are orders on both sides of the board.
- It does not guarantee: that the share price is shielded from falling. A market maker is not a price floor.
- It does not guarantee: that you can buy or sell any size at any moment. The commitment has a ceiling.
- It does not guarantee: that a ticker never enters a queue. Buy and sell queues are the output of supply and demand meeting the daily price band, not evidence that the market maker is absent.
Put differently, a market maker works on keeping a share tradeable, not on keeping it profitable. Any reading that turns the presence of a market maker into a price floor is a wrong reading.
What a dedicated market-making fund is
The common vehicle for this role is the dedicated market-making investment fund (صندوق سرمایهگذاری اختصاصی بازارگردانی): a fund that deploys its resources to make a market in one or several specified tickers. Its resources are typically supplied by the major shareholder, group companies, or affiliated financial institutions, and because the fund is a registered financial entity, its assemblies and decisions are published on Codal like any other issuer. (For how an Iranian exchange-traded fund is structured and why its board price can drift from the value of its holdings, see Sahmino's lesson on gold funds, what they cost, and why the board price drifts from NAV.)
That public filing requirement is exactly what produces those 62 calendar rows, for example the ordinary general meeting of the Isatis Pouya dedicated market-making fund, whose notice was filed on Codal on 12 Mordad 1405 (3 August 2026). For a retail shareholder, the value of these filings is not the fund's name; it is that the resources and financial decisions behind a ticker's market-making commitment are public and traceable.
Outlook
This section is analytical judgment, not reporting. As long as the daily price band remains part of the structure of trading on the Tehran exchange, queues will remain part of a shareholder's daily experience, and market making cannot and is not meant to remove them. What market making can change is the condition of ordinary days: the days when a ticker is in neither a buy queue nor a sell queue, and the quality of the board decides what your trade costs. Judging a market maker rests on those days, not on one-sided ones.
Bottom line
A market maker has one commitment, and that commitment is presence on both sides of the board within a defined volume, spread and resource framework, not holding up a price. The picture from 3 August 2026 in Bank Mellat shows the distinction in a single frame: a price locked all day at 1,199 rials, 1.138 billion shares sitting behind the buy queue, and a sell side that stayed empty across all five rows. The one thing to remember is this: a market maker has a ceiling on its commitment, and once that ceiling is filled, the depth of the board is whatever the market itself has built.
What to watch
This list is observation only and is not buy or sell advice:
- A ticker's order book on ordinary days rather than queue days: how many rows are filled on each side, and the distance between the best bid and the best ask.
- Market-making notices and the assemblies of dedicated market-making funds on Codal, which are also listed in Sahmino's events calendar.
- How a ticker behaves before and after a change of market maker, or a change in the resources of the fund attached to it.
- The ratio of traded volume to average volume, as a signal of whether the board's depth is thinning.
Every figure in this report carries its own date and refers either to the trading session of Monday, 3 August 2026 (12 Mordad 1405) or to the window from 13 July to 3 August 2026. The Tehran Stock Exchange was closed on Tuesday, 4 August 2026 for the Arbaeen holiday.
