Marc Rubinstein from Net Interest on the Financial Sector

Episode Summary

Executive Summary: Andrew Walker interviews Mark Rubenstein, founder of Net Interest, about his path from equity research to long/short financials investing and into newsletter writing, then uses that lens to discuss banks, regulation, fintech, SPACs, and market structure. Rubenstein argues that post-crisis regulation and low rates turned banks into macro trades, boosted exchanges, trapped value in firms like Wells Fargo and Deutsche Bank, and created winners such as exchanges and certain fintech infrastructure models.

Main Topics: Mark Rubenstein’s career path and the origin of Net Interest (Priority: 5/5): Rubenstein traces his career from sell-side bank equity research in Europe to buy-side financials investing, through the financial crisis, then to consulting and launching Net Interest during COVID as a weekly financial-sector newsletter with historical depth. The financial crisis as a front-row financials-only opportunity (Priority: 5/5): He explains how being focused solely on financials let him spot early signs of subprime deterioration in 2006-07 and exploit dispersion across banks, brokers, and regions during the crisis. How regulation and low rates changed bank investing (Priority: 5/5): Rubenstein argues that higher capital requirements, provisioning changes, and ultra-low rates turned banks into a macro-driven, lower-dispersion asset class, reducing traditional long/short opportunities and trapping capital. Winners and losers from regulation: exchanges, banks, and fintech (Priority: 4/5): The conversation explores how exchanges benefit from bank regulation, how big banks gained scale advantages in crisis response, and why fintech challengers have not uniformly displaced incumbents despite expectations. Wells Fargo, Deutsche Bank, and trapped capital (Priority: 4/5): Walker and Rubenstein debate whether undervalued banks can rerate when regulators block buybacks, M&A, and capital returns, framing minority-shareholder discounts and liquidation limits as core valuation issues. Wirecard, fraud detection, and market skepticism (Priority: 4/5): Rubenstein discusses Wirecard as both a cautionary fraud and a lesson in how high-multiple companies, regulators, and shorts can interact, highlighting the pressure placed on investigative journalists and skeptics. SPACs and the shift from public to private markets (Priority: 5/5): He frames SPACs as a mechanism to access abundant private-company supply amid shrinking public markets, while warning that the structure lowers scrutiny and amplifies hype and financial engineering.

Key Arguments: The financial crisis started in financial services earlier than the broader market realized, allowing financials specialists to detect and trade around stress before 2008. Post-crisis regulation and ultra-low rates compressed dispersion across bank stocks globally, making financials behave more like a macro trade than a stock-picking universe. Banks now hold more capital and provision earlier than they did pre-crisis, which helped them absorb the COVID shock better than many expected. Fiscal and central-bank interventions broke the link between unemployment and credit losses, preventing the classic bank panic scenario during COVID. Regulation often creates unintended beneficiaries; in this episode, exchanges have benefited from bank-focused rules and from shifts in listing mechanisms. Large banks gained share because they had the scale, infrastructure, and regulatory standing to distribute relief quickly during the pandemic, while many fintechs struggled to match that reach. Wells Fargo illustrates how a bank can become a 'minority shareholder behind the government' when regulators restrict buybacks, dividends, and M&A, justifying a persistent valuation discount. Deutsche Bank and similar large banks are too big to liquidate easily, which traps capital and limits the classic value-investing remedy of breaking up or winding down a distressed asset. Wirecard shows how fraud can be sustained by high multiple narratives, analyst pressure, and weak market skepticism even when investigative evidence accumulates. SPACs are a response to a mismatch: too many private companies and too few public ones; they also function as a lower-scrutiny alternative to IPOs, increasing the chance that hype outruns fundamentals. In fintech, the most durable opportunities are not just prettier interfaces; they include speed, regulatory arbitrage, and genuinely new financial products such as user-acquisition financing or salary-access solutions. Public markets and private markets operate on different logics, but SPACs and IPOs are the bridge between them; as public supply shrinks, mechanisms to access private growth become more attractive.

Data Points: Net Interest launch timing: March or April (roughly 2020) - Walker says Rubenstein began publishing Net Interest during the COVID era, after consulting projects dried up. Financials-only fund tenure: About 10 years - Rubenstein says he worked on a financial-services long/short fund through the crisis and beyond until 2016. Financial crisis early warning period: 2006-2007 - He says subprime stress was visible in 2006 through early payment defaults and New Century’s collapse in February 2007. New Century bankruptcy: February 2007 - Cited as an early sign of subprime deterioration. Visa IPO: March 2008 - Rubenstein notes the fund was involved in Visa’s IPO during the crisis period. Financial crisis dispersion reference: Q1 2009 - He describes wide dispersion among brokers and banks, with Goldman strong and Citigroup weak. Bank stock valuation example: JPMorgan at 1.7x tangible book; Wells Fargo at 0.7x tangible book - Walker contrasts valuations while discussing regulatory constraints and future upside. Unemployment level discussed: Around 10% - Walker references current unemployment in comparing COVID with the financial crisis. Public companies trend: Public market supply has halved over 20 years - Rubenstein cites a Mobiuson/Mobius-style report on public-to-private market shifts. Private-to-public ratio: About 7 private companies to every 1 public company - He uses this to explain why SPACs and other access mechanisms are growing. Robinhood balance sheet recency: End of 2019 - Rubenstein notes the last filed balance sheet he had seen was pre-COVID. Margin lending risk: A lot of margin lending - He points to Robinhood’s balance sheet and customer behavior as a regulatory concern. Revolut customer base: 13 million customers - Mentioned as an early fintech company he saw at Series A stage. SPAC cash held in trust: $10 per share - Walker explains the standard SPAC structure: investors put up $10 per share that sits in cash until a deal is announced or money is returned. KCAC SPAC reaction: Stock moved from $10 to $18 - Walker cites a same-day SPAC deal announcement in electric vehicles/batteries as an example of market excitement. Nikola stock move: From $10 to $70 - Used as an example of speculative SPAC enthusiasm. WeWork valuation example: $50 billion attempted IPO valuation - Walker references WeWork’s failed IPO as a contrast to easier SPAC access.

Pivotal Quotes: "You’re a minority shareholder behind the government." — Mark Rubenstein: On why bank stocks like Wells Fargo can trade at persistent discounts when regulators control capital allocation. "This was kind of Narnia." — Mark Rubenstein: He uses this metaphor to describe the private-market world that SPACs and IPOs connect to public investors. "It comes back to this idea that there’s no... because the flip side is... capital gets trapped." — Mark Rubenstein: On why large banks like Deutsche Bank can remain cheap for long periods despite apparent liquidation value.

Implications: For investors, the big lesson is to look beyond headline valuations and focus on regulation, capital allocation, and market structure. In banking and fintech, size, policy, and access to distribution may matter as much as earnings power. SPACs and private-market bridges can amplify hype, so skepticism and balance-sheet analysis remain essential.