What Fluct does

Fluct (株式会社fluct) is a Tokyo-based Supply-Side Platform (SSP) that intermediates digital advertising between more than 17,000 media and app publishers on the supply side and a broad set of programmatic demand sources on the buy side. Founded in June 2008 (originally as adingo, renamed Fluct in August 2015) and headquartered at Toranomon Hills Station Tower with an additional office in Naha, Okinawa, Fluct is a wholly-owned subsidiary of publicly-listed CARTA HOLDINGS and employs 51-100 people. Its core product, fluct SSP, has been in market since 2010 and routes inventory to Google Open Bidding, PubMatic OpenWrap (exclusive partner in Japan), TikTok Pangle, ADPOPCORN and other OpenRTB buyers.

Fluct's platform architecture centers on a header bidding wrapper (BID STRAP, built on Prebid) that unifies demand sources for publishers, augmented by DATA STRAP for reporting, DataCurrent for data exchange, and Publisher DataHub/Audience Link for audience packaging. Adjacent products extend the surface beyond display: GOLDSPOT for video/animation, fluct instream video for app, fluct Audio Advertising, Retail Ad Manager for retail media networks, and Publisher Curate Hub for curated deals. In June 2026 Fluct became Japan's first SSP to implement AWS RTB Fabric, and in April 2026 it jointly demonstrated Originator Profile technology with Japan's Ministry of Internal Affairs and Communications.

Fluct monetizes via auction-based take rates on programmatic transactions routed through its SSP, supplemented by curation and retail media fees from Media Curate Dashboard (launched with Dentsu Digital Global Center in December 2025). The customer base is a long-tail mix of more than 17,000 publishers plus a small number of named enterprise relationships, most prominently Yahoo! Japan. Third-party AI integrations (SpiderAF for fraud detection, Browsi for behavioral optimization, GliaStudio for AI video) are embedded into the platform without disclosed proprietary AI development. Growth is funded and supported through CARTA HOLDINGS, with no external funding required at this stage.

Name

Fluct

Legal name

株式会社fluct

Website

https://corp.fluct.jp

Company type

Private

Founded year

2008

Operating status

Operating

Headcount range

51–100 employees

Short description

Fluct is a Tokyo-based Supply-Side Platform (SSP) and wholly-owned CARTA HOLDINGS subsidiary that intermediates programmatic advertising for more than 17,000 publishers in Japan via header bidding wrappers, curation, retail media, audio and reward-ad inventory.

Ownership category

akta.pro rank

Headquarters

HQ city

Toranomon

HQ country

Japan

HQ region

Asia

Offices2 records

Markets served

GTM type

B2B

Offering type

Software

Cost components

Technology or R&D, Personnel, Infrastructure, Marketing or Sales, Operations

Revenue model

1. Programmatic Advertising Revenue Share: Fluct earns revenue by charging publishers a fee or taking a commission on the advertising revenue generated through its SSP platform. The platform connects publishers with advertisers through programmatic bidding, with revenue generated on a per-impression or per-click basis.
2. Ad Tech Services: Additional services including header bidding implementation, data management, and optimization consulting for publishers.

Pricing tiers

Go-to-market motion2 records

Distribution channels3 records

Marketing channels4 records

Core offering

Fluct operates a Supply-Side Platform (SSP) that enables web publishers and mobile app developers to monetize digital advertising inventory through programmatic channels. The platform connects publishers with multiple DSPs, ad networks, and ad exchanges, offering header bidding wrappers, automated reporting, data exchange, and yield optimization. It serves over 17,000 media outlets and apps primarily in Japan, with reach into Asia and North America.

Product overview

Fluct operates as a media consulting and adtech company offering a platform-plus-modules architecture built around its core SSP (Supply-Side Platform). The main offerings include fluct SSP (the core ad server and yield management system), Open Bidding (Google-certified exchange partnership), DATA STRAP (automated reporting), BID STRAP (header bidding wrapper), GOLDSPOT (video ad platform), DataCurrent (data exchange), and specialized solutions for LINE Mini Apps, retail media, reward advertising, and publisher data activation. The company focuses on publisher growth support, helping web and app media maximize advertising revenue through programmatic advertising technology.

Differentiator

Problem solved

Functional benefit

Brands

• fluct SSP: SSP (Supply-Side Platform) for publishers to maximize ad revenue
• BID STRAP
• DATA STRAP
• Open Bidding
• GOLDSPOT
• DataCurrent
• Publisher Curate Hub
• fluctリワードパッケージ
• リテールアドマネージャー

Products and services

• fluct SSP Supply-Side Platform (SSP) enabling publishers to manage, optimize, and monetize digital advertising inventory across multiple demand sources including DSPs and ad networks. Industry-leading number of DSP connections with rich formats and impression-based billing at premium prices.
• Open Bidding Google-certified Open Bidding exchange partner service. Connects with publishers across Japan, Asia, and North America supporting all formats (banner, video, native) for both brand and performance campaigns.
• DATA STRAP
• BID STRAP
• GOLDSPOT
• DataCurrent
• Retail Ad Manager
• Publisher Curate Hub

Quantifiable outcome

• Serves over 17,000 publishers and apps

Named customers1 record

Segments2 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration27 records

AI capability6 records

Feature3 records

Partnerships

Three partnerships are on record, tiered flagship and core.

• CARTA HOLDINGSflagshipStrategic or Co-development PartnerCARTA HOLDINGS is the parent company of Fluct, providing strategic direction, shared resources, and integration within Japan's largest digital advertising group. Fluct operates as a key subsidiary focused on SSP and publisher monetization solutions.
• Yahoo! JapancoreTechnology or IntegrationYahoo! Japan integrates with Fluct's SSP platform for programmatic advertising and publisher monetization, representing a significant demand partner for publisher inventory.
• GooglecoreTechnology or IntegrationFluct is recognized by Google with an Innovation Award and integrates with Google's advertising ecosystem including DSP partnerships and ad exchange connectivity.

Scale indicators2 records

Recent moves9 records

Expansion highlights6 records

Direct peers

• Equativ: Equativ (formerly Smart AdServer) is a global independent SSP and ad server offering supply-side platform services, header bidding, and curation tools. It competes with Fluct in the publisher monetization technology stack across multiple geographies.
• OpenX: OpenX is a global SSP providing supply-side platform services, header bidding, and ad exchange technology for publishers. It is directly comparable to Fluct in offering programmatic monetization tools to web and app publishers across multiple regions.
• Index Exchange: Index Exchange is a global independent SSP operating one of the largest header bidding exchanges, serving premium publishers worldwide. It competes directly with Fluct's BID STRAP and SSP offerings in supply-side auction infrastructure.
• Magnite: Magnite is the largest independent global SSP (formed by the merger of Rubicon Project and Telaria), serving publishers with programmatic header bidding and CTV inventory. It is the most direct competitor to Fluct in supply-side programmatic advertising, with similar product offerings across header bidding and exchange services.
• Geniee: Geniee is a Japanese adtech company operating SSP, DSP, and ad network products with strong presence in mobile and video advertising. It directly competes with Fluct for Japanese publisher inventory and programmatic advertising budgets.
• FreakOut Holdings: FreakOut Holdings is a publicly-traded Japanese digital advertising technology company operating DSP, SSP, and ad network services. It is one of Fluct's most direct domestic competitors in the Japanese adtech market, with overlapping publisher and advertiser offerings.
• MicroAd (MicroAd BRIDGING): MicroAd (now operating as MicroAd BRIDGING) is a Japanese adtech company offering SSP, DSP, and data management services. It is a domestic peer competing with Fluct for Japanese publisher relationships and programmatic advertising market share.
• PubMatic: PubMatic is a leading global SSP with strong presence in header bidding via its OpenWrap SDK solution. Notably, PubMatic has an exclusive Japan sales partnership with Fluct for OpenWrap SDK, demonstrating direct overlap in supply-side technology and Japan operations.

Others

• The Trade Desk: The Trade Desk is the largest independent global DSP and a key demand-side partner that connects to Fluct's SSP inventory via RTB. While not a direct SSP competitor, The Trade Desk is a critical buyer of Fluct's publisher inventory and a key partner in the programmatic ecosystem.

Broad incumbents

• Google Ad Manager: Google Ad Manager is Google's integrated ad server and SSP/exchange product, serving as the dominant broad incumbent in supply-side programmatic advertising globally and in Japan. While Fluct is a certified Google Open Bidding partner, Google Ad Manager remains the largest competitive force across the publisher monetization stack.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xx.com/fluct_pr
• Facebookfacebook.com/fluct.jp?locale=ja_JP
• LinkedInlinkedin.com/company/fluct

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles7 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Fluct