Block Positioner

What Is Block Positioner?

A block positioner is a dealer who, in order to facilitate a customer's large purchase or sale that could disrupt the market, takes positions for their own account in the hopes that they might eventually turn a profit.

Key Takeaways

  • A block positioner is a dealer who, in order to facilitate a customer's large purchase or sale, takes positions for their own account
  • Aside from preventing potential market disruption, block positioners seek to profit from their actions.
  • Block positioners aim to unload the position quickly, and typically use hedging strategies—such as arbitrage techniques or options—to reduce the risk associated with positions.
  • Traditionally, prime brokers have played the role of block positioner, agreeing to commit capital to their clients (such as hedge funds) in order to facilitate block trades for them.

Understanding Block Positioner

Traditionally, prime brokers have played the role of block positioner, agreeing to commit capital to their clients (such as hedge funds) in order to facilitate block trades for them, although a few other broker-dealers have also carved out a niche in executing block trades.

Block trades, also called block orders, are large orders in the underlying bond or stock that a client seeks to execute in its entirety. Because of their large size, these trades may artificially move the market. Traders who get wind of the block order may try to front-run the sale—a possibly illegal and unethical move that would hurt the firm handling the block trade.

Block trades on the open market demand caution on the part of traders. They are usually conducted through an intermediary such as a block positioner rather than a hedge fund or investment bank.

Types of Block Positioners

Sometimes, the block positioner can be an inter-dealer broker (IDB). This broker takes on an agency role and tries to cobble together a group of counterparties, each of which is willing to participate in some portion of the trade without committing capital. This is often the case in options markets, where a trader may seek to buy or sell thousands of contracts.

Other times, the block positioner is a client's prime broker which will agree to take the entire trade at once. These trades may also be executed through dark pools or electronic communication network (ECN) matching systems. This prevents the disruption of regular market activity that would happen by introducing a large trade.

Sometimes, a prime broker will ask a specialized block positioner situated on the floor of a stock exchange—known as a wholesale broker—to "cross" a large number of shares of stock at a pre-determined price, which may be different from the current market price. Often, these wholesale brokers will operate on "away exchanges," such as the Philadelphia Stock Exchange.

Regulations Governing Block Positioners

Block positioners take on considerable risk in exchange for the profits they seek. Any firm involved in block positioning must:

  • Register as a broker or dealer with the Securities and Exchange Commission (SEC) and also with the New York Stock Exchange (NYSE) if it is a member firm.
  • Comply with Rule 15c3-1 for market makers and have a minimum available capital of $1 million.
  • Engage in buying, or selling short, from or to a customer a block of stock with a current market value of $200,000, or more, to facilitate a sale or purchase by that customer.
  • Seek to sell the shares comprising the block as quickly as possible and meet other regulatory conditions prior to the sale of that block.

The dealer takes on the risk of the securities in order to help clear the trade for the seller. Block positioners aim to unload the position quickly, and typically use hedging strategies, such as arbitrage techniques or options, to reduce the risk associated with positions.

Article Sources

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  1. NYSE. "Membership." Accessed Aug. 1, 2021.

  2. U.S. Securities and Exchange Commission. "Guide to Broker-Dealer Registration." Accessed Aug. 1, 2021.

  3. FINRA. "NET CAPITAL REQUIREMENTS FOR BROKERS OR DEALERS SEA Rule 15c3-1." Accessed Aug. 1, 2021.

  4. U.S. Securities and Exchange Commission. "§ 240.3b–8." Accessed Aug. 1, 2021.