Instruments and data
The short instrument has its own economics.
Separate market exposure, cash distributions, option payoffs and daily resets. Import complete histories for additional securities and base currencies.
These illustrations do not replicate a named ETF. A real fund’s prospectus, borrow, distribution policy and execution terms remain necessary.
Import weekly history ↓Short payoff and carrying costs
Choose the structure and change its assumptions. Daily-reset and covered-call funds are modelled separately from an ordinary funded exposure.
A covered call retains downside and gives up gains above the strike in exchange for a premium; a short of that structure reverses its payoff and carries short-sale risks. Daily-reset compounding depends on the path and is not a guaranteed decay trade. Ordinary and daily-reset illustrations deduct the fund fee from each post-return daily value; the covered-call illustration estimates the fee on its initial value because interim option marks are unavailable. See OIC covered-call mechanics and the SEC leveraged and inverse ETF bulletin.
Reconcile a short position
Use dated prices and actual cash distributions to check a fixed-share short. This ledger is separate from the synthetic fund illustrations and the portfolio’s adjusted-return proxy.
Use calendar dates in increasing order; the first row has no distribution. Each later distribution belongs to the interval ending on that row. Borrow and rebate accrue on the previous observed price times fixed units for the elapsed calendar days. Sparse marks approximate daily accrual; intraday execution, changes in borrow rate, tax and settlement terms are excluded. These inputs are used for the request and are not saved as a decision.
International and additional histories
Saved US histories can be used directly in USD. Other currencies or instruments need a complete checked import. Every holding must pass the same alignment rules.
CSV format
symbol,date,close,currency,fx_to_base,distribution,name,sector,country
Use 157–1,200 consecutive completed Friday closes per instrument. Required columns are symbol, date, close and currency. Use a unique identifier for each listing, such as a ticker with an exchange suffix. FX is base-currency units per unit of local currency, on every observation. Example: CHF 1 = USD 1.20 means fx_to_base = 1.20 for a USD portfolio.
The optional distribution column is the cash paid per share during the week ending on that row. For adjusted closes it must be zero or blank because distributions are already embedded. For separate distributions, prices and payouts must use the same split-adjusted units. Convert pence and other minor price units before importing.
Optional metadata must stay identical within each instrument. Country is declared metadata, not revenue exposure. Imports are private new vintages; they do not change shared source data. Duplicate weeks, missing FX, non-finite numbers, incomplete windows and unusual price moves stop the import. Successful validation confirms consistency, not independent verification against company filings or an exchange.
Limit: 2 MB, 100 instruments, 50,000 observations. Only completed weekly histories are accepted; no interpolation or estimated daily marks. Extend the same histories with later observations to maintain prospective decision records.