- prior the 1980s, when you bought a stock a physical stock certificate was passed back and forth between your broker and the broker selling the stock
- as you can imagine, as trading volumes increased this became unmanageable. In fact, at one point, the exchanges would close every Wednesday just to give people time to catch up on all of the exchange of certificates
- everyone, rightly, agreed that there needed to be a better way and the idea of a clearing house emerged. In this model, all of the physical certificates lived in one place. Ownership was tracked via a central "database" (originally not electronic). This made it MUCH easier to transfer ownership aka "settle". This is very similar to how gold is traded e.g. the NY Fed holds it for other countries etc
- An added benefit of a clearing house: it's easy to see how much everyone owns of everything. e.g. if one party is over leveraged or has gone extremely short, in theory, the clearing house can choose to not deal with that party or, more flexibly, request additional capital etc.
Here is also a specific example about settlement risk:
- let's say you report all of your trades to your clearing broker (think of them as a mini-clearinghouse)
- a data file gets lost or corrupted and the clearing broker says "Wait! Something is wrong! We are not letting you trade until we get this figured out!"
- EVEN IF YOU ARE CORRECT and they are wrong, you now have market risk because you may be holding a position that is losing you money. So much money in fact that it might drive you out of business.
The above is an actual answer to a settlement expert when asked "What is your nightmare scenario?". This in turn, could have ripple effects to other clearing brokers and trading firms and is generally all part of "settlement" or "clearing' risk.
Source: have worked in fintech trading for many years.
Thanks for the background info. Why can't the database be updated ~instantly though? Is it just because of legacy systems that handle settlement in periodic (daily?) batches?
Also, couldn't a broker eliminate this risk by just making assets "unavailable to trade" until they've been settled? Granted, I understand why brokers wouldn't want to do that under normal circumstances, but it seems like something they should be able to enable when liquidity becomes a problem.
To me, "Your cash can't be spent yet because the TSLA sale you just made hasn't settled" would seem a lot more understandable than "We're halting GME purchases".
> Why can't the database be updated ~instantly though? Is it just because of legacy systems that handle settlement in periodic (daily?) batches?
The legacy systems reason is a big one. There are banks with mainframes built in the 80's as part of the critical infrastructure. Another reason is that everyone doesn't communicate directly with the main clearing house. e.g. brokers clear with other brokers who then clear with the clearing house etc.
> To me, "Your cash can't be spent yet because the TSLA sale you just made hasn't settled" would seem a lot more understandable than "We're halting GME purchases".
There have been interesting solutions to disputes. e.g. I think it was NYMEX that had a rule for floor traders along the lines of "If Trader A and Trader B have a clearing issue, NEITHER of them gets to trade till it is taken care of." Given that these traders traded with each other multiple times a day coupled with they were making no money during this dispute, both parties were incentivized to come to an agreement.
- prior the 1980s, when you bought a stock a physical stock certificate was passed back and forth between your broker and the broker selling the stock
- as you can imagine, as trading volumes increased this became unmanageable. In fact, at one point, the exchanges would close every Wednesday just to give people time to catch up on all of the exchange of certificates
- everyone, rightly, agreed that there needed to be a better way and the idea of a clearing house emerged. In this model, all of the physical certificates lived in one place. Ownership was tracked via a central "database" (originally not electronic). This made it MUCH easier to transfer ownership aka "settle". This is very similar to how gold is traded e.g. the NY Fed holds it for other countries etc
- An added benefit of a clearing house: it's easy to see how much everyone owns of everything. e.g. if one party is over leveraged or has gone extremely short, in theory, the clearing house can choose to not deal with that party or, more flexibly, request additional capital etc.
Here is also a specific example about settlement risk:
- let's say you report all of your trades to your clearing broker (think of them as a mini-clearinghouse)
- a data file gets lost or corrupted and the clearing broker says "Wait! Something is wrong! We are not letting you trade until we get this figured out!"
- EVEN IF YOU ARE CORRECT and they are wrong, you now have market risk because you may be holding a position that is losing you money. So much money in fact that it might drive you out of business.
The above is an actual answer to a settlement expert when asked "What is your nightmare scenario?". This in turn, could have ripple effects to other clearing brokers and trading firms and is generally all part of "settlement" or "clearing' risk.
Source: have worked in fintech trading for many years.