Arithmos
Define index construction frameworks
Get notified of more jobs like this · No spam, ever
How your CV stacks up
Upload your CV to see how well it fits this job role
?%
All roles lead
Full-time
Open role
Arithmos
Head of Custom Index Solutions
Define a new category in retail investing. Own the investment thesis that everything else hangs off.
London (hybrid) Full-time £280,000–£310,000 base
3.0%–4.0% equity significant performance bonus
About Arithmos
Arithmos is building the retail layer for direct indexing. We turn a plain-English idea into a transparent, rule-based portfolio with institutional-grade backtesting and analytics. Our goal is to make structured investing accessible to millions.
The role
You will own the investment layer of Arithmos — how indices are constructed, how they are presented, and how users trust and adopt them. This is a senior leadership role combining quant expertise, product thinking, and client-level communication.
What you’ll do
- Define index construction frameworks
- Thematic indices (AI, energy, defence, etc.)
- Factor-based and rule-based strategies
- Oversee portfolio methodology
- Weighting logic
- Rebalancing strategies
- Constraints and optimisation
- Ensure outputs are institutionally credible and transparent
- Every published index traceable back to its rules
- Every metric defined and reproducible
- Partner with product and engineering
- Translate investment logic into scalable systems
- Shape how Arithmos communicates investing — simplify complex strategies into intuitive outputs
- Act as a public-facing authority
- Content, thought leadership, partnerships
- Represent Arithmos in institutional conversations
Reasons to use Rodeo
Start with a chat, not a search bar
Grad scheme, placement, apprenticeship? Not sure what you want yet — that's fine. Your agent talks it through with you and turns "I have no idea" into a shortlist.
It searches the market for you
Every day your agent scans the market matching roles against what actually matters to you, not just keywords on a CV.
Only hits
No noise. No "maybe this fits." Just roles with a clear explanation of why they're right — and where to focus when applying.
Requirements
- 7–15+ years in hedge fund / asset management / quant research
- Strong background in portfolio construction, index design, and systematic investing
- Proven ability to translate complex strategies into clear frameworks
- Strong communication skills (both technical and non-technical)
Nice to have
- Experience building or managing index products
- Experience working with institutional clients
- Public presence (content, speaking, publishing)
Why this role is exceptional
- Define a new category in investing (retail direct indexing)
- High ownership over product + investment strategy
- Significant equity upside tied to company growth
- Opportunity to become a recognised voice in modern portfolio construction
Get help with your application
Your very own career expert that helps elevate your application to the next level.
Compensation & Benefits
- £280,000–£310,000 base
- 3.0%–4.0% equity
- significant performance bonus
- Private healthcare
- 25 days holiday + bank holidays
- Top-tier equipment
- Flexible working
- Annual company offsite
How to apply
Upload your CV and a short note — no more than 200 words — on why this role in particular. If you have work you’re proud of that’s relevant (a product you shipped, a research paper, a backtest you ran), link to it. Two-stage process: screening call, then a take-home + technical deep-dive with the team you’d join.
Applying for Head of Custom Index Solutions
Your name Email
LinkedIn (optional) Portfolio / recent work (optional)
Why this role (≤200 words) CV (PDF, DOC, DOCX, TXT or RTF — max 5 MB)
no file selected
We’ll only use this to review your application and reply to you.
Arithmos is an equal-opportunity employer. Published 24 April 2026.
“It took my CV and asked me questions relevant to understanding what kind of jobs to suggest for me. Suggestions were almost perfect. Jobs were exactly what I’ve been looking for.”
Jessica, London
Skills
Location