Questions
Data
Why doesn’t Rearview include data?
Because you’d pay for it whether you used it or not. Bundled data comes with a licence that renews every year, and that cost usually ends up in the price as a subscription. Rearview reads the data you choose instead, through a documented format any source can feed: free exports to explore, and a survivorship-free feed with delisted stocks and index history when you’re ready to trade on the results. Your data stays on your Mac. The trial includes ten years of synthetic sample data, so you can try everything before you bring your own.
What data works?
Anything you can write as CSV in the import format: securities, prices as they traded, corporate actions and index membership, as daily bars or intraday bars down to a minute. Per-symbol files, such as Yahoo, Stooq or AmiBroker exports, convert in one step with Data Library ▸ Import ▸ Per-Symbol Files… or rvw convert ohlcv, and the converter says what such files can’t tell the engine, such as delistings. Futures contracts convert into chains that roll with rvw convert futures. Sharadar’s tables convert with Data Library ▸ Import ▸ Sharadar Files…, and Norgate Data users can export with Rearview’s Norgate export script.
For results you’d trade on, use a survivorship-free source that includes delisted stocks and index membership by date. Most data vendors’ terms allow personal use only.
The Sharadar converter, the futures converter, the Norgate export script and the calendars of exchanges outside the US have so far been tested on vendors’ samples and on files made to their published layouts, not yet on full downloads. If one of yours doesn’t import, write to support and it gets fixed.
Does it handle delisted stocks, splits and dividends?
Yes. Rearview stores prices as they traded and works out split- and dividend-adjusted prices itself, using only the past. A stock that was acquired closes at its last price; one delisted for poor performance closes with a haircut you set. A file that simply ends is never treated as a delisting. Every report lists the assumptions it used.
What happens to my results when I update my data?
When the update only adds new days, every earlier run still reproduces, byte for byte. That holds for a whole new export and for a daily file holding only the newest days. When an update changes past prices, Rearview names each change and the first day it shows, before anything is replaced, and you can keep both versions.
Trading
What can it test?
Stocks and ETFs, on one exchange or several, each on its own days, in an account in any currency your data has rates for. Coins, long only, in fractions. Futures, as chains that roll from one contract to the next. Forex pairs, which earn or pay carry. Daily bars, or intraday bars down to a minute for stocks and ETFs. Options aren’t modelled.
Does Rearview place orders or give signals?
No. It tests rules you write on data you supply. After a run it can list the next session’s orders for you to place yourself, as a readable list or an Interactive Brokers basket file. It never connects to a broker and gives no advice.
Can it follow what I actually trade?
Yes. A live account reads your broker’s file, an Interactive Brokers Flex Query or a simple CSV, and replays your fills beside the backtest of the same days, so you see how far ahead or behind you are and which orders you missed or placed late. Its next-day orders come from what you actually hold. A live account follows one script on daily bars, in the account’s currency; futures and forex pairs can’t be traded live yet. The Interactive Brokers files, Flex Queries and basket files, have so far been tested on files made to Interactive Brokers’ published layouts, not yet on a real account’s.
Can it scan for today’s candidates?
Yes. A scan lists the securities that meet your conditions on a day, with every value it worked out, best ranked first. A strategy can list its own entry candidates the same way, and the day’s choices of a run say why it did or didn’t buy each one.
Can it do the evening’s work by itself?
Yes. The evening routine updates your data, reads each live account’s broker file, writes the next session’s orders and runs your scans, on a schedule you set. It stops at the first thing that needs you, such as a change to past prices, and it never places an order.
Can it test short selling and margin?
Yes: short entries and exits, borrow fees (one rate, or a rate per stock and day), dividends charged on shorts, an optional rebate on short proceeds, Reg T-style margin with maintenance checks, and forced liquidation. Futures and forex pairs can be held on margin as a share of their value, or backed in full with cash. Coins are never shorted. The short-sale price test (Rule 201) isn’t modelled, and the documentation says so.
How does it know a result isn’t luck?
It can’t know for sure, and it doesn’t pretend to. It counts every variation you tried, earlier runs and previews in the project included, and reports two statistics built for the question, the Deflated Sharpe Ratio and the Probability of Backtest Overfitting, with every input shown. Then it gives one of three plain verdicts: probably not luck, can’t tell, or probably luck. A single run can also be set against 500 runs with random entries, and stress-tested with costs doubled, signals a day late, entries missed and other start days. Tries made outside Rearview can’t be counted, and it says so.
Mac and privacy
Which Macs does it run on?
Macs with Apple silicon, running macOS 26 or later. There’s no Windows or Linux version.
Do I need an account? What does Rearview send?
No account. The app sends no telemetry and no usage data; it goes online only to check for updates and to download one you choose, and Buy… and Renew Updates… open this website. After a crash it offers a report, which reaches us only if you email it yourself. Your strategies, data and results stay on your Mac, and the licence is checked on your Mac. See Privacy.
Can I use AI to write strategies?
Yes, with your own AI tool. The language reference is one page an AI coding agent can read, and rvw check --json lets it check and fix its own scripts. Rearview itself makes no AI calls and holds no AI keys.
Buying
How does the licence work?
One payment of $349 ($249 at the founder price) buys lifetime use of the version you buy and a year of updates. After that, updates are $149 a year if you want them, and the app keeps working without them. Correctness fixes are free to every licence holder. A licence is for one person, on the Macs they use, for their own trading. See Pricing.
What if I change my mind?
You can have a refund within 30 days of buying, no questions asked. See Refunds.
What happens if Rearview is discontinued?
If we decide to stop maintaining it, we first release a final version with the licence check removed, so the app keeps working. Your scripts are plain text and your runs are plain files, so your work is never locked in.