Biggest Decliners on the TSE YTD 2025

November 02, 2025

Biggest Decliners

The biggest decliners on this list have had the greatest percentage decrease in share price year to date. This means each stock has seen its share price decline at a faster rate than the rest of the market so far this year. Companies that are experiencing dramatic decreases in share price can do so for a variety of reasons, including the sector they are in has turned (such as companies in an unfavorable commodities space or a sector that has been disrupted), or the company is experiencing financial difficulties generally due to an inability to service its debt.

Toronto Stock Exchange

The Toronto Stock Exchange (TSE) is a stock exchange located in Toronto, Ontario, Canada. It is the 10th largest exchange in the world and the third largest in North America based on market capitalization.

About the Data

This table includes the top companies based on their percentage decrease in share price year to date.

How do you use this table?

The biggest decliners are companies with downward momentum and potentially higher reward as a short position. These stocks tend to have a higher trading volume and visibility in the marketplace. Stocks in this group can change direction quickly and tend to be short term trades. Stocks in this category are generally sold to preserve capital or held for speculation or a short position.

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SymbolNameTotal ReturnPeriod
OPT Optiva Inc -77.09 YTD
APS Aptose Biosciences Inc -75.79 YTD
TLRY Tilray Brands Inc -68.95 YTD
NEXT NextSource Materials Inc -65.75 YTD
ONC Oncolytics Biotech Inc -65.41 YTD
DII.B Dorel Industries Inc -64.01 YTD
FOOD Goodfood Market Corp -61.84 YTD
BCT BriaCell Therapeutics Corp -61.81 YTD
FLOW Flow Beverage Corp -61.76 YTD
FORA VerticalScope Holdings Inc -59.03 YTD
All data provided as at market close May 29, 2025.

Company Details

Optiva Inc

OPT:TSX

Total Return

-77.09

Period

YTD

Optiva Inc is engaged in offering software products to the telecommunications software market. The company's portfolio of products enables real-time billing, charging, policy management and user experience that are critical to customers' growth and performance.

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Aptose Biosciences Inc

APS:TSX

Total Return

-75.79

Period

YTD

Aptose Biosciences Inc is a clinical-stage biotechnology company committed to discovering and developing personalized therapies addressing unmet medical needs in oncology. The company's small molecule cancer therapeutics pipeline includes products designed to provide single agent efficacy and to enhance the efficacy of other anti-cancer therapies and regimens without overlapping toxicities.

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Tilray Brands Inc

TLRY:TSX

Total Return

-68.95

Period

YTD

Tilray is a Canadian producer that cultivates and sells medical and recreational cannabis. In 2021, legacy Aphria acquired legacy Tilray in a reverse merger and renamed itself Tilray. The bulk of its sales are in Canada and in the international medical cannabis export market. US exposure consists of CBD products and alcohol.

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NextSource Materials Inc

NEXT:TSX

Total Return

-65.75

Period

YTD

NextSource Materials Inc is a strategic materials development company based in Toronto, Canada. The Company has two operating segments, consisting of mine development and BAF development. No commercial revenues have been generated by the Companys' segments. The company's Molo graphite project in Madagascar is one of the widely known and highest-quality graphite deposits globally and contains SuperFlake graphite. The company also holds an interest in Green Giant Vanadium Project.

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Oncolytics Biotech Inc

ONC:TSX

Total Return

-65.41

Period

YTD

Oncolytics Biotech Inc is a clinical-stage biopharmaceutical company. The company is focused on the discovery and development of pharmaceutical products for the treatment of cancers that have not been treated with therapeutics. It is developing pelareorep, an immunotherapeutic agent that improves the ability of the immune system to fight cancer, making tumors more susceptible to a broad range of oncology treatments.

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Dorel Industries Inc

DII.B:TSX

Total Return

-64.01

Period

YTD

Dorel Industries Inc is a Canadian company that sells juvenile products and furniture. Its reporting segments include Dorel Home and Dorel Juvenile. Maximum revenue is generated from the Dorel Juvenile segment, which is engaged in the design, sourcing, manufacturing, distribution, and retail of children's accessories which include infant car seats, strollers, high chairs, and infant health and safety aids.

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Goodfood Market Corp

FOOD:TSX

Total Return

-61.84

Period

YTD

Goodfood Market Corp is an online grocery company in Canada that delivers fresh meal solutions and groceries that make it easy for members to enjoy delicious meals at home every day. The principal business activity is focused on developing and servicing the online meal kit and grocery add-on market. Goodfood members have access to products and exclusive pricing made possible by its direct-to-consumer fulfillment ecosystem that eliminates waste and retail overhead.

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BriaCell Therapeutics Corp

BCT:TSX

Total Return

-61.81

Period

YTD

BriaCell Therapeutics Corp is a clinical-stage immuno-oncology company. The group is developing an entirely new class of targeted immunotherapies to transform cancer care. Its product candidate Bria-IMT, is being evaluated in a pivotal Phase 3 combination study for metastatic breast cancer (MBC is breast cancer that has spread to other tissues). Bria-IMT is a targeted cell-based immunotherapy.

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Flow Beverage Corp

FLOW:TSX

Total Return

-61.76

Period

YTD

Flow Beverage Corp is a health and wellness-focused beverage company at the convergence of three important trends in the consumer-packaged goods industry including, functional ingredients, sustainable packaging and supply chain and premium quality. It markets its premium alkaline spring water in Canada and the United States in original unflavoured and a range of organic flavors in various sizes.

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VerticalScope Holdings Inc

FORA:TSX

Total Return

-59.03

Period

YTD

VerticalScope Holdings Inc is a technology company that operates a cloud-based digital community platform comprising hyper-focused apps, forums, marketplaces, editorial, and e-commerce rating and brand review websites.

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Optiva and Aptose Biosciences were the biggest decliners on the TSE YTD. See all the biggest decliners on the blog: https://www.stockcalc.com/Blog/biggest-decliners-tse-ytd-2025
Optiva $OPT and Aptose Biosciences $APS were the biggest decliners on the #TSE YTD. See the full list of decliners: https://www.stockcalc.com/Blog/biggest-decliners-tse-ytd-2025
Optiva and Aptose Biosciences were the biggest decliners on the TSE YTD. See all the biggest decliners on the blog: https://www.stockcalc.com/Blog/biggest-decliners-tse-ytd-2025

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