How to Buy CytomX Therapeutics, Inc. (CTMX) Stock

Where to buy CTMX

15 brokers in our matrix offer CTMX (penny/OTC-friendly subset). Verify availability and current fees with each broker before trading.

Broker	Commission	Fractional	Extended	Overnight	Options	OTCQX	OTCQB	Pink Cur.	Pink Ltd.	Grey	Surcharge	Short locate
FirstradeReview	$0	~4,000+ tickers, ≥ $5		~1,200	$0	Full	Full	Full	Full	Limited	—	limited
Interactive BrokersReview	$0 (Lite) / per-share (Pro)			~10,000	per-contract pricing	Full	Full	Full	Full	Full	Per-share pricing applies	best
TradeStationReview	$0 listed				$0.50 / $0.60	Full	Full	Full	Full	Limited	$0.005/share OTC (TS Select/TS Go), $0 up to 10,000 shares	strong
Charles Schwab (thinkorswim)Review	$0	Schwab Stock Slices, S&P 500 only, ≥ $5/slice, up to 30 at once		~1,130	$0.65	Full	Full	Full	Limited	Limited	Variable service fees on certain restricted	moderate
E*TRADE (Morgan Stanley)Review	$0 listed			~20	$0.65	Full	Full	Full	Full	Limited	$6.95 flat on penny stocks	moderate
FidelityReview	$0	Stocks by the Slice, 7,000+ stocks/ETFs, from $1			$0.65	Full	Full	No	No	No	—	limited
Merrill EdgeReview	$0				$0.65	Full	Full	Full	Limited	No	—	none
MoomooReview	$0				$0	Limited	Limited	Limited	No	No	—	limited
Public.comReview	$0				rebate model	Limited	Limited	Limited	No	No	—	none
SoFi Active InvestingReview	$0				$0	Full	Limited	Limited	No	No	—	none
tastytradeReview	$0 stocks				$1.00 open, $0 close (capped at $10 per leg)	Limited	Limited	Limited	No	No	—	limited
WebullReview	$0				$0	Limited	Limited	Limited	No	No	—	limited
CenterPoint SecuritiesReview	Per-share (day-trader oriented)				per-contract	Full	Full	Full	Full	Full	Per-share	best
Cobra TradingReview	Per-share (day-trader oriented)				per-contract	Full	Full	Full	Full	Full	Per-share	best
SpeedTraderReview	Per-share (day-trader oriented)				per-contract	Full	Full	Full	Full	Full	Per-share	best

24-Hour / Overnight trading

CTMX may be eligible for overnight trading via Charles Schwab (thinkorswim), Interactive Brokers, Robinhood, E*TRADE (Morgan Stanley), Webull, Moomoo, Firstrade. Each broker maintains its own eligibility list — confirm before placing an order.

Penny stock / OTC routing

CTMX trades on the OTC markets. Broker support varies sharply by tier (OTCQX, OTCQB, Pink Current, Pink Limited, Grey). Fidelity and Robinhood exclude pink/grey entirely. For short-locate on small-caps, Interactive Brokers and the day-trader specialists (Cobra Trading, SpeedTrader, CenterPoint) have the deepest inventory.

About CytomX Therapeutics, Inc.

CytomX Therapeutics Inc a clinical-stage, oncology-focused biopharmaceutical company developing novel, masked, conditionally activated biologics designed to be localized to the tumor microenvironment. It is engaged in developing antibody therapeutics based on probody technology platforms. The company's probody technology platform creates proprietary cancer immunotherapies against clinically-validated targets and develops cancer therapeutics. Probody therapeutics are designed to take advantage of conditions in the tumor microenvironment to enhance the tumor-targeting features of an antibody and reduce drug activity in healthy tissues.

Sector

PHARMACEUTICAL PREPARATIONS

Employees

69

Headquarters

SOUTH SAN FRANCISCO, CA

Listed

2015-10-08

Market cap

$809.85M

Frequently asked

Where can I buy CytomX Therapeutics, Inc. (CTMX)?

CTMX is offered by 15 brokers in our matrix, including Firstrade, Interactive Brokers, TradeStation, Charles Schwab (thinkorswim), E*TRADE (Morgan Stanley). Compare commissions, fractional eligibility, and overnight availability in the broker matrix above.

Can I buy CTMX after hours or overnight?

Yes. CTMX is on the 24-hour eligibility list for Charles Schwab (thinkorswim), Interactive Brokers, Robinhood, E*TRADE (Morgan Stanley), and others. Overnight sessions route through ATSs with wider spreads and limit-orders only.

Does Robinhood offer CTMX?

No. Robinhood does not provide access to the OTC tier CTMX trades on. Interactive Brokers, TradeStation, and Firstrade have the broadest OTC coverage.

Does Fidelity offer CTMX?

Partial. Fidelity's OTC access is tier-limited — see the OTC columns in the matrix to check whether CTMX's specific tier is supported.

Does Webull offer CTMX?

Partial. Webull's OTC access is tier-limited — see the OTC columns in the matrix to check whether CTMX's specific tier is supported.

Is CTMX optionable?

Yes. CTMX has listed options contracts. Per-contract pricing varies by broker — see the Options column in the matrix.

Is there a tokenized version of CTMX?

Not in our current dataset. The tokenized stock universe (Kraken xStocks, Binance Alpha/Ondo, Robinhood EU, Hyperliquid HIP-3) is expanding quickly — we refresh quarterly.

Can I buy a fractional share of CTMX?

Yes. Multiple brokers in the matrix support fractional shares for CTMX — see the Fractional column above for per-broker eligibility and minimums.