Terms of Service

1. Who you are contracting with

These terms are the agreement between you and 2Sigma for your use of the 2Sigma service at 2sigma.study. By creating an account, or by buying credits, you accept them.

2Sigma is run from Israel by an individual trader (osek), not by an incorporated company, so there is no company number to give.

Questions and notices, including a cancellation under section 6, reach us at [email protected]. We answer there rather than by telephone.

2. What the service is

2Sigma serves you past-exam questions from your course, adapts what it serves to how you are doing, and gives you an AI tutor ("Sigmund") that talks you through a question and grades your answer.

Sigmund is an AI, not a person, and it can be wrong. Scores, feedback, explanations and study recommendations are study aids. They are not a guarantee that an answer is correct, not a prediction of your grade, and not a substitute for your course's own material or your instructor.

3. Who may use it

You must be 18 or older to use 2Sigma. By signing in you confirm that you are. The account is yours personally; do not share your login, and tell us promptly if you think someone else has used it.

4. SIG credits

Credits are the unit you spend inside the service. They are shown as SIG.

• One SIG buys one submitted answer. Skipping a question costs nothing, and talking with the tutor while you work on a question is included.
• SIG credits expire 12 months after you acquire them. This applies to purchased credits, trial credits and credits from a coupon alike. When a pack expires, any SIG left in it is gone. Credits are spent oldest pack first.
• SIG have no cash value, cannot be transferred to another account, sold or exchanged for money, except where we refund a purchase under section 6.
• If an AI evaluation fails through a fault on our side, the credit is returned to you automatically.

5. Prices and payment

All prices are shown including 18% Israeli VAT. There are no other charges, and no subscription — you buy a pack of credits when you want one.

The pricing page shows what each pack costs and how many SIG it carries. The price shown there when you buy is the price that applies, and the checkout screen shows you the pack and the total before you pay.

Prices are charged in shekels; any dollar figure shown is an approximate conversion for convenience. Payment is taken by PayPal, which sends you the receipt. Credits are added to your balance as soon as PayPal confirms the payment.

6. Cancelling and refunds

Buying credits from us is a distance sale under the Israeli Consumer Protection Law, 5741-1981.

• You may cancel within 14 days of the purchase and get your money back.
• We may deduct a cancellation fee of 5% of the purchase price or ₪100, whichever is lower, as the law permits.
• We refund the value of the credits you have not used. Credits you have already spent on a submitted answer have been supplied, and are not refunded.
• To cancel, email [email protected] from the address on your account. We refund through PayPal, to the account you paid from.
• If you have a disability, are a senior citizen or a new immigrant, the law gives you a longer cancellation window — tell us and we will apply it.

Nothing here limits any right you have under the Consumer Protection Law or its cancellation regulations. Where these terms and that law disagree, the law wins.

7. How you may use the service

Use 2Sigma to study. Do not:

• resell, redistribute or publish the questions, solutions or tutor output;
• scrape the service, or access it through anything other than the interface we provide;
• share an account, or use someone else's;
• try to break, overload or work around the service's limits, or to extract material you have not paid for;
• upload anything unlawful, or anyone else's personal details.

We apply rate limits to keep the service available and to control the cost of AI calls. Hitting them is not a fault.

8. Content

The courses, questions, solutions and everything else we present remain ours or our licensors'. You get a personal, non-transferable right to use them to study for as long as your account is open. Past-exam material is used for educational purposes and remains the property of the institution that set it.

What you write and draw stays yours. You give us the permission we need to store it, show it back to you, send it to our AI provider for grading and tutoring, and use it to run and improve the service — described in full in our Privacy Policy.

9. Availability, changes and termination

We aim to keep 2Sigma available but we do not promise uninterrupted service; we may take it down for maintenance, and we may change or discontinue features.

You may close your account at any time. We may suspend or close an account that breaks these terms, or that we reasonably believe is being used fraudulently. If we close your account without you having broken these terms, we refund the unused credits in it.

We may change these terms. We will post the new version here with a new date, and we will tell you before a change that materially affects you takes effect. If you do not accept a change, stop using the service and ask us to refund your unused credits.

10. Liability

We provide the service with reasonable care, but as an educational aid and without any warranty that its content or its AI output is accurate or complete. Your results are your own.

To the extent the law allows, our total liability to you for any claim connected with the service is limited to the amount you paid us in the 12 months before the claim. Nothing here excludes liability that cannot be excluded by law, including for death or personal injury caused by negligence, for fraud, or under the Consumer Protection Law.

11. Law and jurisdiction

These terms are governed by the law of the State of Israel, and the competent courts of Israel have jurisdiction. If you are a consumer resident elsewhere, this does not deprive you of the protection of the mandatory consumer rules of the country you live in.