Terms of Use

“Arithmos”, “we”, and “our” refer to the Arithmos service operated at arithmos.xyz. We provide an online investment research and data platform that lets users describe a theme in plain English and generates a transparent, rule-based hypothetical basket of public equities together with historical backtest data.

Arithmos is an information and research tool. Nothing on the platform — including index outputs, backtests, attribution analysis, news summaries, AI-generated commentary, blog posts, leaderboards or any other content — constitutes investment advice, a personal recommendation, an offer to buy or sell any security, or a solicitation of any kind.

We do not consider your individual financial circumstances, objectives, tax position, suitability or appropriateness. We are not authorised or regulated by the Financial Conduct Authority or any other financial regulator and we do not carry on any regulated activity under the UK Financial Services and Markets Act 2000 (or equivalent legislation in any other jurisdiction). You should consult an authorised financial advisor before making any investment decision.

Arithmos does not execute trades on your behalf, does not act as a broker, does not hold client money, does not hold or custody client assets, and does not auto-invest or auto-rebalance any portfolio. The hypothetical baskets we generate are research outputs only — if you choose to act on them you must do so yourself through your own regulated broker, at your own discretion and risk.

You must be at least 18 years old to use Arithmos. By creating an account you confirm that you are using the service for your own research purposes and that doing so is lawful in your jurisdiction. We may suspend or terminate accounts at our discretion, including where we believe the service is being used unlawfully or in breach of these terms.

You are responsible for keeping your sign-in credentials confidential and for all activity that occurs under your account. Notify us promptly via the contact form if you believe your account has been compromised. You may not share, sell or transfer your account.

You agree not to: scrape or bulk-export data beyond fair personal research use; reverse engineer the platform; submit prompts intended to manipulate other users, defame third parties, or generate unlawful content; use the platform to provide regulated investment advice or discretionary management to others; or otherwise interfere with the security or integrity of the service.

The Arithmos platform, brand, code, methodology and generated content (other than user-supplied prompts and metadata) are owned by Arithmos or our licensors. You retain ownership of the prompts and inputs you submit; by submitting them you grant us a worldwide, royalty-free licence to process them in order to provide the service and to improve our models.

Indexes you mark as public may be displayed on community surfaces (feed, leaderboard, your profile). You can change visibility at any time from the index detail page.

Pricing, fundamentals, news and reference data are sourced from third-party providers. We use commercially reasonable efforts to surface accurate data but make no warranty as to its accuracy, completeness or timeliness. Backtests are simulated using historical data and may differ from real-world results — see the backtest methodology page for full caveats.

Some features are available only on paid plans. Pricing, billing cycles and any committed terms are shown at checkout and are processed by Stripe. You may cancel future renewals at any time from /settings; cancellations take effect at the end of the current billing period and we do not provide pro-rata refunds for partial periods unless required by law.

The service is provided “as is” and “as available” without warranty of any kind, whether express or implied, including warranties of merchantability, fitness for a particular purpose, or non-infringement. We do not warrant that the service will be uninterrupted, error-free, or that any output is suitable for your purposes.

To the maximum extent permitted by law, Arithmos is not liable for any indirect, incidental, special, consequential or punitive damages, or for any investment losses, lost profits, lost data, or lost opportunity arising out of or relating to your use of the service. Our aggregate liability for any claim arising out of or relating to the service is limited to the amount you paid us for the service in the twelve months preceding the event giving rise to the claim.

Nothing in these terms excludes or limits liability that cannot lawfully be excluded or limited (including liability for fraud or for death or personal injury caused by negligence).

You agree to indemnify Arithmos against any third-party claims arising from your misuse of the service, your breach of these terms, or your violation of any law or third-party right.

We may update these terms from time to time. Material changes will be notified by email or in-product banner. Continued use of the service after the effective date of an update constitutes acceptance of the updated terms.

These terms are governed by the laws of England & Wales. The courts of England & Wales have exclusive jurisdiction to settle any dispute arising from or in connection with these terms or the service.

Questions about these terms? Use the contact form.