Trading halted as U.S. stocks plummet • Hacker News Board

Re: Trading halted as U.S. stocks plummet

#211

Post by londons_explore » Mon, Mar 09, 2020, 5:25 PM UTC

bilekas wrote: post #189

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

Okay thats fine, but who implements/decides these circuit breakers ? And what purpose to they serve only to limit a mass sell off ? Nice point about only 2 daily. But still seems crazy.

Really it's just saying "the market is now closed". But you can still sell those securities on other markets or direct to someone who wants to buy or sell.

Re: Trading halted as U.S. stocks plummet

#212

Post by _se » Mon, Mar 09, 2020, 5:25 PM UTC

isoskeles wrote: post #196

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. Then why does L2 exist? It seems redundant, L1 would get triggered before L2, and only one can occur in a single day, so why have L2 at all? What am I missing here? Edit: Also, anyone who downvoted me for posting the same question as someone at the same minute, you know what to do.

See my other response to a similar comment - I will edit the original.

Re: Trading halted as U.S. stocks plummet

#213

Post by [deleted] » Mon, Mar 09, 2020, 5:25 PM UTC

jagged-chisel wrote: post #199

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. I don't follow. You'd hit 7% before 13%, so how would L2 ever execute?

[deleted]

Re: Trading halted as U.S. stocks plummet

#214

Post by [deleted] » Mon, Mar 09, 2020, 5:25 PM UTC

jagged-chisel wrote: post #199

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. I don't follow. You'd hit 7% before 13%, so how would L2 ever execute?

[deleted]

Re: Trading halted as U.S. stocks plummet

#215

Post by TeMPOraL » Mon, Mar 09, 2020, 5:25 PM UTC

jagged-chisel wrote: post #199

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. I don't follow. You'd hit 7% before 13%, so how would L2 ever execute?

As I understand GP: L1 and L2 can each fire only once per day. So if you hit L1, and after a brief rebound the market still goes down, you'll hit L2. If after that it still keeps falling, it'll get stuck at L3.

Re: Trading halted as U.S. stocks plummet

#216

Post by [deleted] » Mon, Mar 09, 2020, 5:25 PM UTC

isoskeles wrote: post #196

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. Then why does L2 exist? It seems redundant, L1 would get triggered before L2, and only one can occur in a single day, so why have L2 at all? What am I missing here? Edit: Also, anyone who downvoted me for posting the same question as someone at the same minute, you know what to do.

[deleted]

Re: Trading halted as U.S. stocks plummet

#217

Post by seanmccann » Mon, Mar 09, 2020, 5:25 PM UTC

jagged-chisel wrote: post #199

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. I don't follow. You'd hit 7% before 13%, so how would L2 ever execute?

We hit 7% earlier today. If we hit 7% again today, nothing will happen. If we hit 13% we hit L2.

Re: Trading halted as U.S. stocks plummet

#218

Post by burlesona » Mon, Mar 09, 2020, 5:26 PM UTC

bilekas wrote: post #180

Genuine question: They can just do that ? Issue a trading halt because they don't like the direction it's going ? > “There’s a reason why they have those circuit breakers -- it’s to give people time to come back from panicked feelings,” Seems strange that the market is kinda able to be manipulated like that. I'm not saying this is a bad move, just surprised that someone can do it.

In large part these are designed to break the feedback loops that can happen in automated high frequency trading and give humans a chance to look at things. These policies were implemented by all the stock exchanges after flash crashes triggered by ML algorithms encountering something "weird" and going into hard sell mode.

https://en.wikipedia.org/wiki/Flash_crash

Re: Trading halted as U.S. stocks plummet

#219

Post by jilles » Mon, Mar 09, 2020, 5:26 PM UTC

jagged-chisel wrote: post #199

_se wrote: post #186

Earlier quoted context omitted.

"They" don't do anything - this is called a circuit breaker, and is automatically triggered. There are three breakers: L1 - 7% down before 3:25pm - 15 minute halt L2 - 13% down before 3:25pm - 15 minute halt L3 - 20% down - halted for the remainder of the day Only a single L1 and a single L2 breaker can occur in a single day, e.g. the market falling below 7%, rising, then falling again will not trigger a second L1 br…

> Only a single L1 or L2 breaker can occur in a single day. I don't follow. You'd hit 7% before 13%, so how would L2 ever execute?

L1 hit today and there was a 15 minute halt this morning. If the S&P continues to plunge and hit -13% during today, there will be another 15 minute halt.

Re: Trading halted as U.S. stocks plummet

#220

Post by 3fe9a03ccd14ca5 » Mon, Mar 09, 2020, 5:26 PM UTC

totaldude87 wrote: post #184

To be honest , the market was in dire need for correction, BUT wonder where we will be when companies starts reporting their quarterly results and impact of that. So far this looked more like a correction than a precursor to the recession. To make things worse, OPEC dropped bombs which spread the wildfire further..

Oil dropping because an opec monopoly explodes is good news for most of the economy (outside of oil industries obviously). But a drop in crude because of demand is bad for everybody.