Hi @Clash , I too have some money in CSH2, so was interested to research. My interpretations follow.
It is a ‘synthetic’ not a ‘physical’ etf - so it doesn’t actually own anything.
Instead Lyxor enters into a loan contract with, currently, Societe Generale.
Basically, our money goes to help fund Societe Generale’s activities, being loaned on a short-term basis. In return, Lyxor gets paid interest on the loan, and Societe Generale puts up a basket of shares in various companies as collateral, if they should fail.
Societe Generale looks to pay as little as they can for using our money for a while. Lyxor asks for the most interest it can get. Both can take their business elsewhere. So, it is a market, and the interest rate in the market will fluctuate with supply and demand.
The overall market for these types of short-term loans will generally have a similar rate. SONIA is an index giving the average of the available rates, so Lyxor can be pretty confident in offering us that return. SONIA will fluctuate with the prevailing rate in the market. CSH2 tracks SONIA not the BoE rate.
Given SONIA has tended to a positive value, linked funds have gone up over time, though at a varying rate. The etf itself is subject to market forces too though, so its price fluctuates around that upward trend. It is an investment so carries some risk though - there are no guarantees that it will always go up.
Regarding end-of-day dips - generally, prices offered for ETFs drop towards the end of the day, because buyers have no time to sell on, so they will carry the overnight risk of a price drop. The reduced price covers their risk somewhat, until they can sell the next day.
There are no stupid questions - it is valid to want to understand your investments and risks.
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