<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>lordnacho</author><text>Former FX fund manager here. I believe the allegations.&lt;p&gt;What happens is that most derivatives like options or variance swaps are tied to the daily WM&amp;#x2F;Reuters fixing in the London afternoon. There&amp;#x27;s a bunch of different types of derivatives, but the thing about most of them is they have some sort of characteristic where the price dependency gets highly nonlinear towards an expiry.&lt;p&gt;So this means that someone who had a moderately sensitive position on one day might have an extremely sensitive position a few days later.&lt;p&gt;To the point where it might make sense to make sure the price doesn&amp;#x27;t hit a certain level at the fixing, by doing a bunch of trades in the spot market leading up to the fix. Or conversely by making sure it does hit some level by ramping up the price.&lt;p&gt;Now you might think it&amp;#x27;s all more or less a wash, because someone is gonna have the other side of that derivative, but that&amp;#x27;s not the case. The banks tend to have the same sides of the trades against their customers, because the customers are mostly all after certain payoff schemes.&lt;p&gt;Apart from there being a motivation, I also believe the allegations because I&amp;#x27;ve been told the actual positions on certain days. You&amp;#x27;d have these days where nothing was happening at all, and then just before the fix the price would ramp, or the price would be moving but the graph would have a weird flat ceiling. So you&amp;#x27;d call the brokers and ask him WTF happened, and they&amp;#x27;d say something like &amp;quot;XYZ bank has a huge barrier there&amp;quot;, or &amp;quot;Bank X has wants to knock out this level&amp;quot;.&lt;p&gt;It&amp;#x27;s very apparent to anyone who looks at any product that has a fixing, I&amp;#x27;ve traded several (Swaps, FX, Equity Derivs). You start by thinking it&amp;#x27;s just noise and there&amp;#x27;s always someone in the office who will say that, but after a while you get suspicious of it happening at the same time, plus you have the broker rumours lining up. It would be great if the free market were restored.</text><parent_chain></parent_chain></comment><story><title>Big investors sue banks in U.S. over currency market rigging</title><url>https://www.reuters.com/article/uk-forex-lawsuit/big-investors-sue-16-banks-in-u-s-over-currency-market-rigging-idUSKCN1NC34J</url></story>
<instructions>Your goal is to analyze the following comment and estimate how highly it will be upvoted by the Hacker News community.</instructions><comment><author>saosebastiao</author><text>I&amp;#x27;m curious to know what sort of timeframes they were manipulating on. Most if the large institutional banks are operating as market makers, which would likely limit their influence on price movements to a few pips at most. Most institutional investment firms in forex are not trading as market makers though...typically operating on much larger time horizons...hours to days. The amount of capital necessary to manipulate the currency on those timeframes is incomprehensible. I doubt even the 16 largest banks in the world, even working as a deal facto cartel, could coordinate price manipulations bigger than 50 pips over the course of a day. I mean we&amp;#x27;re talking about a quarter of the GDP of the entire US changing hands every single day via these markets. These banks are massive, but still nowhere near big enough to materially affect the markets. It makes me wonder what sort of damages are being claimed, and how they are calculating those damages.</text><parent_chain></parent_chain></comment><story><title>Big investors sue banks in U.S. over currency market rigging</title><url>https://www.reuters.com/article/uk-forex-lawsuit/big-investors-sue-16-banks-in-u-s-over-currency-market-rigging-idUSKCN1NC34J</url></story>