Prothena PLC - (PRTA)'s last earnings report was on August 6, 2026.

Prothena PLC - Earnings Dates, Upcoming and Historical

Name: PRTA Earnings Dates
Creator: Market Chameleon

A table for both the upcoming quarterly earnings releases and historical releases for PRTA, if available. Projected earnings dates are based on past patterns. For stocks that list options, we compare the market's implied earnings effect against the actual earnings effect in the stock price.

PRTA last reported earnings on August 6, 2026 after the market close (AMC). The company held a conference call for investors at on . PRTA shares gained +2.1% the day following the earnings announcement to close at 8.76. Following its earnings release, 82 days ago, PRTA stock has drifted -4.1% lower. From the time it announced earnings, PRTA traded in a range between 7.80 and 9.87. The last price (8.40) is closer to the lower end of range.

Next PRTA Earnings Date: PRTA is estimated to announce earnings between November 6, 2026 and November 12, 2026 (the company has not announced a date yet and the estimate is based on historical earnings dates).

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Earnings Dates Frequently Asked Questions

Where can I find PRTA historical earnings dates?

In the historical earnings table above, you can find PRTA historical earnings dates and the historical stock price reactions to those earnings. Additionally, you can find the time of day of the earnings release (i.e. Before Market Open or After Market Close) and the historical conference call date and time.

Where can I find PRTA historical predicted earnings moves vs actual moves?

In the historical earnings table above, in the column labeled "Implied Straddle", you will see the percentage move that was expected for the earnings based on the options at-the-money straddle price. Furthermore, you can see a before and after price effect comparison in PRTA earnings. The "Implied Straddle" column will show you what the market expected the stock price move to be before the earnings release and the "Price Effect" column will show you what the actual stock price move was after the release. This will give you a good idea of how good the market place is at predicting the stock price reaction of an earnings report for PRTA.

When is PRTA next Earnings date?

In the upcoming earnings table above, you will see the next earnings date along with a status; Announced (if the company issued a press release with the upcoming date) or Projected (a prediction of the next earnings date based on historical information).

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The following list contains earnings trade ideas based on PRTA historical stock behavior around earnings releases.

View By Risk Type:All·Defined Risk·Undefined Risk

	Earnings Strategy			Historical Strategy Backtest Results					Current Strategy Market & Theoretical Value
Earnings Date	Strategy Type The type of the selected earnings option strategy. All strategies are assumed to be Long (buying) unless otherwise noted. ATM = At-the-Money (nearest strike to the spot price) ATM Straddle: buying or selling 1 call and 1 put on the same strike for the strike nearest to the at-the-money price for that expiration. ATM Call: buying or selling 1 call on the strike nearest to the at-the-money price for that expiration. ATM Put: buying or selling 1 put on the strike nearest to the at-the-money price for that expiration. 25-Delta Call: buying or selling 1 call on the strike nearest to the 25-delta (out-of-the-money) for that expiration. 25-Delta Put: buying or selling 1 put on the strike nearest to the 25-delta (out-of-the-money) for that expiration. 75-Delta Call: buying or selling 1 call on the strike nearest to the 75-delta (in-the-money) for that expiration. 75-Delta Put: buying or selling 1 put on the strike nearest to the 75-delta (in-the-money) for that expiration. Bull Call Spread: buy 1 call on the at-the-money strike and sell 1 call on the 25-delta strike for that expiration. Bear Put Spread: buy 1 put on the at-the-money strike and sell 1 put on the 25-delta strike for that expiration. Strangle: buying or selling 1 call on the 25-delta (out-of-the-money) strike and 1 put on the 25-delta (out-of-the-money) strike for that expiration. Ratio Call Spread: sell 1 call on the at-the-money strike and buy 2 calls on the 25-delta strike for that expiration. Ratio Put Spread: sell 1 put on the at-the-money strike and buy 2 puts on the 25-delta strike for that expiration. Buy-Write ATM: buy the underlying stock and sell 1 call on the at-the-money strike for that expiration. Buy-Write 25-Delta: buy the underlying stock and sell 1 call on the 25-delta (out-of-the-money) strike for that expiration. Call Butterfly Spread: sell 2 calls on the at-the-money strike, buy 1 call on the 25-delta strike (out-of-the-money), and buy 1 call on an in-the-money strike which is equidistant from the at-the-money Put Butterfly Spread: sell 2 puts on the at-the-money strike, buy 1 puts on the 25-delta strike (out-of-the-money), and buy 1 puts on an in-the-money strike which is equidistant from the at-the-money Call Condor Spread: sell 1 call on an out-of-the-money strike and 1 call on an in-the-money strike, and then buy 1 call on a deeper out-of-the-money strike and 1 call on a deeper in-the-money strike which are equidistant from the previously mentioned inner strikes. Ex: if the stock price is $100, sell on the $90 strike and the $110 strike, and buy on the $85 strike and the $115 strike Put Condor Spread: sell 1 put on an out-of-the-money strike and 1 put on an in-the-money strike, and then buy 1 put on a deeper out-of-the-money strike and 1 put on a deeper in-the-money strike which are equidistant from the previously mentioned inner strikes. Ex: if the stock price is $100, sell on the $90 strike and the $110 strike, and buy on the $85 strike and the $115 strike Long Stock Only: what would have happened if you simply bought the underlying stock and no options.	Historical Open Range The start day of the strategy timeframe, relative to the earnings date. If the earnings results are released before market open (BMO), the day of earnings trading would be the same calendar date. If results are released after the close (AMC), the day of earnigns would be the next trading day. If earnings is released Tuesday AMC, the Day of Earnings would be Wednesday, and 1 Day Before would be Tuesday.	Historical Close Range The end day of the strategy timeframe, relative to the earnings date. If the earnings results are released before market open (BMO), the day of earnings trading would be the same calendar date. If results are released after the close (AMC), the day of earnigns would be the next trading day. If earnings is released Tuesday AMC, the Day of Earnings would be Wednesday, and 1 Day After would be Thursday.	# of Obs The number of historical observations available for the selected strategy and timeframe, up to 12. Observations are dependent upon the options meeting market width requirements -- if the markets are too wide, we can't calculate an accurate value of the options, and therefore it would be skipped.	Win Rate % The percentage of observations that the specified strategy gained value over the specified timeframe	Avg Return For this timeframe, the average return of the specified strategy over the set of observations	Median Return The median percentage return of the specified strategy over the set of observations, for the specified timeframe	Sharpe Ratio The average return divided by the standard deviation, a high positive value is considered a good result	Next Open Date	Next Close Date	Option Expiration The expiration date of the options involved in the selected strategy. Hover over the expiration date for more details on which strikes are included in this strategy, and their current market price.	Current Market	Theoretical Value The theoretical value of the option strategy, using the Historical Price Return Distribution for Intervals Around Earnings. The historical distribution uses up to 10 years' worth of historical earnings dates to build a theoretical value. For more info on this, visit the Historical Price Return Distribution page under the Stocks menu.	Theoretical Edge The difference between the Theoretical Value of the strategy and the Current Market Price of the strategy. If negative, this analysis would suggest an expected loss by executing the strategy.

Today's Actionable Earnings Strategies

Opportunities are drawn from our Earnings Option Strategy Screener, using the last 12 observations to find the best-performing strategies

Hover over the Current Market column for more details on the strike prices, market prices, and theoretical values of the strategy

Click the link in the Option Expiration column to be taken directly to the Option Chain page for that expiration

Theoretical Value is calculated using an interval-based historical price distribution around earnings. Visit Price Return Distribution for more info

Note: Stock and option trading involves risk that may not be suitable for all investors. Examples contained within this report are simulated and may have limitations. Average returns and occurrences are calculated from snapshots of market mid-point prices and were not actually executed, so they do not reflect actual trades, fees, or execution costs. This report is for informational purposes only, and is not intended to be a recommendation to buy or sell any security. Neither Market Chameleon nor any other party makes warranties regarding results from its usage. Past performance does not guarantee future results. Please consult a financial advisor before executing any trades.

The information is provided for informational purposes only and should not be construed as investment advice. All stock price information is provided and transmitted as received from independent third-party data sources. The Information should only be used as a starting point for doing additional independent research in order to allow you to form your own opinion regarding investments and trading strategies. The Company does not guarantee the accuracy, completeness or timeliness of the Information.