> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vistadex.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Odds Formats

> Understanding how prediction market prices relate to probability and odds

Prediction market share prices directly represent implied probabilities. A YES share priced at \$0.70 implies a 70% probability of the event occurring. This page explains how to interpret prices and convert between common odds formats.

## Price as Probability

The simplest way to think about prediction market prices:

| Share Price | Implied Probability |
| ----------- | ------------------- |
| \$0.05      | 5%                  |
| \$0.20      | 20%                 |
| \$0.50      | 50%                 |
| \$0.80      | 80%                 |
| \$0.95      | 95%                 |

If you think the true probability is higher than the price implies, buying is a positive expected value bet. If you think it's lower, the other side offers value.

## Converting Between Formats

<Tabs>
  <Tab title="To Decimal Odds">
    Decimal odds show your total return per \$1 wagered (including your stake).

    **Formula:** Decimal Odds = 1 / Price

    | Price  | Decimal Odds | Meaning              |
    | ------ | ------------ | -------------------- |
    | \$0.20 | 5.00         | Win 5x your stake    |
    | \$0.50 | 2.00         | Win 2x your stake    |
    | \$0.80 | 1.25         | Win 1.25x your stake |

    **Example:** Buy at \$0.25, decimal odds = 4.00. A \$10 bet returns \$40 if you win (\$30 profit + \$10 stake).
  </Tab>

  <Tab title="To American Odds">
    American odds show profit relative to \$100 wagered.

    **For prices below \$0.50 (underdog):**
    American Odds = (100 / Price) - 100, shown as positive

    **For prices above \$0.50 (favorite):**
    American Odds = Price / (1 - Price) × 100, shown as negative

    | Price  | American Odds |
    | ------ | ------------- |
    | \$0.20 | +400          |
    | \$0.33 | +200          |
    | \$0.50 | +100 / -100   |
    | \$0.67 | -200          |
    | \$0.80 | -400          |
  </Tab>

  <Tab title="To Fractional Odds">
    Fractional odds (common in UK) show profit relative to stake.

    **Formula:** Fractional = (1 - Price) / Price

    | Price  | Fractional Odds |
    | ------ | --------------- |
    | \$0.20 | 4/1             |
    | \$0.25 | 3/1             |
    | \$0.50 | 1/1 (evens)     |
    | \$0.75 | 1/3             |
    | \$0.80 | 1/4             |
  </Tab>
</Tabs>

## Quick Reference Table

| Probability | Price  | Decimal | American | Fractional |
| ----------- | ------ | ------- | -------- | ---------- |
| 10%         | \$0.10 | 10.00   | +900     | 9/1        |
| 20%         | \$0.20 | 5.00    | +400     | 4/1        |
| 25%         | \$0.25 | 4.00    | +300     | 3/1        |
| 33%         | \$0.33 | 3.00    | +200     | 2/1        |
| 50%         | \$0.50 | 2.00    | +100     | 1/1        |
| 67%         | \$0.67 | 1.50    | -200     | 1/2        |
| 75%         | \$0.75 | 1.33    | -300     | 1/3        |
| 80%         | \$0.80 | 1.25    | -400     | 1/4        |
| 90%         | \$0.90 | 1.11    | -900     | 1/9        |