Ask The Experts - Leaders of the Mortgage Servicing Industry Answer Your Questions


Phil Mackintosh
Traders Magazine Online News

What's Fair? It Depends on Your Point of View

Nasdaq's Phil Mackintosh dives into the pricing and mechanics surrounding IBKR's recent listing switch from IEX.

Traders Poll

Should the SEC allow bitcoin-backed ETFs to hit the market?

How can you make sure your algo only does what you want?

If you donít feed the right numbers to your algos, they could start running around the markets, doing all sorts of crazy things. So, how can you get in your algoís head and make sure it only does what you want? For more information, visit


Q: Why would an algorithm chase after block trades in the first place?

A: If a trader has a volume participation benchmark (for example 10%), they want to participate with 10% of the market's volume. An algorithm typically only has access to the electronic markets but looks at all trading activity to know what trades are happening and how much volume it needs to trade in order to be 10% of the overall volume. If an algorithm thinks that it missed out on a large trade it will start to trade more heavily to make up for that missing volume, this type of "catch up" can cause unintended market impact.

Q: How can a trader tell the algorithm the correct block trades to ignore?

A: Traders need algorithms that have access to the correct methodology for block identification in each market. This way they donít need to adjust anything on their algorithm. Tradebook shows traders the average block size in each market using the STAZ function on the Bloomberg Professional(R) service.


About Insight Bites in 60 Seconds

When it comes to stock trading, so much is changing so quickly that it’s difficult to understand and manage all the variables. Whether it’s algorithmic trading, price swings or dark liquidity, The Insight Bites series presents smart and concise snapshots of what a trader can do to address and overcome the most pressing of these challenges. Hosted by Traders Magazine and brought to you by Bloomberg Tradebook, each 60 second animated video provides quick and humorous insight into a unique issue that traders face every day. For more information, visit