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Prothena (PRTA) Stock Chart & Stock Price History

Prothena logo
$8.61 +0.13 (+1.53%)
Closing price 10/8/2026 04:00 PM Eastern
Extended Trading
$8.49 -0.12 (-1.34%)
As of 09:08 AM Eastern
Extended trading is trading that happens on electronic markets outside of regular trading hours. This is a fair market value extended hours price provided by Massive. Learn more.

Prothena Stock Price Performance

The Prothena (PRTA) stock chart highlights key performance trends across multiple timeframes. Over the last 12 months, the stock's price has decreased 16.41%, with a year-to-date return of -9.84%. In the past month, the stock has decreased 7.42%, reflecting recent market activity.

As of the latest close, Prothena traded at $8.61 with a market cap of $450.73 million and volume of 642,381 shares. Five years ago, the stock traded at $71.15, representing a 87.90% decrease over that period. At the time, it had a market cap of $3.14 billion and a volume of 224,566 shares.

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5 Day
Performance
+2.99%
1 Month
Performance
-7.42%
3 Month
Performance
-10.68%
Year-To-Date
Performance
-9.84%
1 Year
Performance
-16.41%
5 Year
Performance
-87.90%

PRTA Stock Chart for Friday, October, 9, 2026

Prothena Stock Price History

Price Date
0 Results
DateOpening PriceClosing PriceHighLowVolumeMarket Capitalization
10/08/2026$8.48$8.61
+1.53%
$8.81$8.36642,381 shs$450.73 million
10/07/2026$8.02$8.48
+5.74%
$8.63$7.88690,409 shs$443.95 million
10/06/2026$8.27$8.02
-3.02%
$8.28$7.80508,306 shs$419.85 million
10/05/2026$8.36$8.27
-1.08%
$8.37$7.91714,460 shs$432.93 million
10/02/2026$8.54$8.36
-2.11%
$8.62$8.35675,837 shs$437.65 million
10/01/2026$8.38$8.54
+1.91%
$8.58$8.35457,083 shs$447.10 million
09/30/2026$8.78$8.38
-4.56%
$8.99$8.37634,528 shs$438.69 million
09/29/2026$8.72$8.78
+0.69%
$8.80$8.59544,740 shs$459.63 million
09/28/2026$8.29$8.72
+5.19%
$8.86$8.07488,857 shs$456.52 million
09/25/2026$8.32$8.29
-0.36%
$8.52$8.19481,047 shs$434.01 million
09/24/2026$8.68$8.32
-4.15%
$8.73$8.28426,062 shs$435.55 million
09/23/2026$8.99$8.68
-3.45%
$8.97$8.67357,807 shs$454.40 million
09/22/2026$8.51$8.99
+5.64%
$9.09$8.70388,515 shs$470.65 million
09/21/2026$8.58$8.51
-0.82%
$8.80$8.46361,902 shs$445.50 million
09/18/2026$8.46$8.58
+1.42%
$8.60$8.251.83 million shs$449.16 million
09/17/2026$8.24$8.46
+2.67%
$8.56$8.23404,757 shs$442.88 million
09/16/2026$8.33$8.24
-1.08%
$8.50$8.20398,335 shs$431.39 million
09/15/2026$8.86$8.33
-5.98%
$8.86$8.30323,437 shs$436.08 million
09/14/2026$8.93$8.86
-0.78%
$8.99$8.79374,872 shs$463.82 million
09/11/2026$9.02$8.93
-1.00%
$9.14$8.77376,273 shs$467.49 million
09/10/2026$9.30$9.02
-3.01%
$9.26$8.97310,811 shs$472.20 million
09/09/2026$9.54$9.30
-2.52%
$9.50$9.22294,558 shs$486.86 million

This page (NASDAQ:PRTA) was last updated on 10/8/2026 by MarketBeat.com Staff.
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