Independent · Beginner-Friendly · Data-Driven

Ambika Iyer

Ambika Iyer

Software Engineer, Self-Taught Investor, Founder of The Rational Investor

How This Started

By training and profession, I am a software engineer. For most of my early career, money was something I earned and thought about only loosely. I was never a big spender, which was a good habit without me consciously knowing it. But I also had no framework for making money work. My savings sat in a savings account earning around 3% a year, and I had never thought to question whether that was enough. I did not know what inflation meant in any practical sense.

In 2016, I was laid off. The context matters: I had just taken on a large home loan. So the combination of a new EMI commitment and a sudden loss of income forced me to actually sit down and look at my finances properly for the first time.

I want to be clear that this was a relatively gentle layoff compared to what many people experience. I was put on a notice period of three months rather than being asked to leave immediately. I found a new job within that period and was never technically unemployed. But those three months were the first time in my working life that I had real mental space outside of work demands, and I used most of it trying to understand money.

That is when I looked properly at what I had. Decent savings, all sitting in a bank account at 3% interest. A home loan. No understanding of inflation, no idea that the money sitting idle was losing real purchasing power every year. The question that kept nagging at me was simple: what do I do with what I have so that the loan does not become a crisis if things go wrong again?

The Learning Journey

I started the way most cautious people start: bank fixed deposits. They felt safe, I could understand them, and they at least earned more than a savings account. But I quickly started wondering whether there was more. I graduated to mutual funds, which introduced me to the concept of equity and the stock market in a managed, lower-risk way.

Eventually I opened a demat account and started buying individual stocks. I had no idea what I was doing. I bought when stocks were running up because that is what every article I read seemed to be saying. I sold when they dropped because panic is a powerful teacher when real money is on the line. I made the standard beginner mistakes.

The shift came from YouTube. I stumbled onto Warren Buffett and Charlie Munger, their Berkshire Hathaway annual meeting talks, Munger's Daily Journal meeting conversations, and the hundreds of videos explaining their philosophy. I spent an enormous amount of time watching people break down how Buffett thinks about businesses. Alongside that I started using tools like Screener.in and TradingView to actually look at company financials and charts, learning both fundamental and technical analysis through a combination of videos and hands-on exploration.

The conceptual shift was significant. Instead of asking "is this stock going up?" I started asking "is this a good business? Does it have a durable competitive advantage? Is it being run well? Am I paying a reasonable price?" These were completely different questions, and they changed how I looked at everything.

I want to be honest: I am still a student. I learn something new every day. I do not read annual reports cover to cover — I use screener.in to navigate the key numbers, TradingView for charts and technicals, and a lot of YouTube content from people who explain financial concepts clearly. I have gone from bank deposits to mutual funds to picking individual stocks in both Indian and US markets, and every step of that journey involved getting things wrong first.

Why This Website Exists

This website is my notes made public.

When I was learning, I kept wishing someone had written a beginner-friendly breakdown of HDFC Bank's business model, or a plain-English explanation of what a P/E ratio actually means in practice, or an honest analysis of NVIDIA that covered both why it was extraordinary and what could go wrong. What I found online was either too shallow to be useful or too technical to be accessible.

So I started writing what I was learning the way I wished it had been explained to me. No jargon without an explanation. No price targets or stock tips. No cheerleading. Just honest, thorough analysis of businesses for someone who is earlier in the learning journey than I am now.

The aim is that if you are where I was in 2016, this site helps you not be caught off guard. Financial literacy is not complicated once someone takes the time to explain it properly. It should not take a layoff to force the conversation.

What This Site Is and Is Not

Everything on this site is published for educational and information-sharing purposes only. None of it is financial advice. None of it is a recommendation to buy or sell any security.

I am not a registered financial advisor, a SEBI-registered research analyst, or an investment professional of any kind. I am a software engineer who became deeply curious about how businesses and markets work, and who shares what she learns. I am still learning and will make mistakes, as any honest person in this space will tell you they do too.

The goal of every article is to give you better tools to think about a company or concept for yourself, not to tell you what to do with your money. If something here helps you ask better questions or understand a business more clearly, it has done its job.

Please do your own research, consult a qualified financial advisor for decisions that matter, and never invest money you cannot afford to lose.

Important Disclaimer

All content published on The Rational Investor is for educational and information-sharing purposes only. Nothing on this site constitutes financial advice, investment advice, or a recommendation to buy or sell any security or financial instrument. Ambika Iyer is not a registered financial advisor or SEBI-registered research analyst. Past performance discussed in any article is not indicative of future results. Investing in securities carries risk, including the possible loss of principal. Always consult a qualified financial professional before making investment decisions.

Articles by Ambika Iyer

From Intel Engineer to India's Samosa King: The Samosa Party Story

How Amit Nanwani and Diksha Pande grew Samosa Party from a Bengaluru side hustle into a 110-outlet, Rs 150 Cr Indian QSR brand across six cities.

Business StoriesApril 28, 2026

From One Store to 100 Crore: Kiran Shah and the GoZero Story

How Kiran Shah left a P&G career to scale Apsara Ice Cream to 100 stores, then quit it all to build GoZero, India's leading sugar-free ice cream brand.

Business StoriesApril 27, 2026

What Really Powers ChatGPT? The Hidden AI Stack Most Investors Have Never Heard Of

From nuclear plants to fiber cables: a beginner's guide to the 8-layer AI supply chain and the public companies in India and USA building each layer.

Investment EducationApril 27, 2026

Makhana: The Superfood Snack Becoming a Multi-Billion Rupee Business

From Bihar's ponds to urban quick-commerce carts, how makhana became India's fastest-growing snack category and what it means for investors.

Investment EducationApril 20, 2026

Brushes, Bullets & Billions: How Social Media Rewrote the Art Supplies Industry

How TikTok, YouTube and Instagram turned a quiet $12B niche into a creator-driven growth machine, and what investors should know.

Investment EducationApril 18, 2026

Valuation 101: When to Buy Great Companies (A Beginner's Guide)

Stock valuation guide: P/E, PEG, DCF, margin of safety. Learn when to buy undervalued stocks using Warren Buffett's framework.

Investment EducationFebruary 9, 2026

Understanding Economic Moats: The 7 Types Every Investor Should Know

Learn Warren Buffett's framework for competitive advantages. Discover the 7 types of economic moats with real-world examples from companies like Google, NVIDIA, and HDFC Bank.

Investment EducationFebruary 9, 2026

TCS: Complete Business Analysis & AI Strategy Guide

TCS stock analysis: IT services empire, competitive moats, AI transformation, and investment thesis - beginner guide to Indian tech stocks.

Stock Deep DiveFebruary 9, 2026

NVIDIA: Complete Business Analysis & AI Infrastructure Guide

NVIDIA stock analysis: gaming GPUs to AI dominance, CUDA moat, and investment thesis - semiconductor platform investing guide.

Stock Deep DiveFebruary 9, 2026

ITC Limited: Complete Business Analysis & Investment Guide

Deep dive into ITC's transformation from tobacco giant to diversified conglomerate - a beginner's guide to understanding multi-business models.

Stock Deep DiveFebruary 9, 2026

How to Read Annual Reports: A Beginner's Guide to Finding Great Investments

How to read annual reports like Warren Buffett: 20-minute framework for analyzing 10-K filings, financial statements, and finding moats.

Investment EducationFebruary 9, 2026

Alphabet (Google): Complete Business Analysis & AI Strategy Guide

Google stock analysis: search dominance, AI transformation, competitive moats, and defending against ChatGPT - beginner investing guide.

Stock Deep DiveFebruary 9, 2026

Understanding P/E Ratios: The Complete Beginner's Guide to Stock Valuation

Master P/E ratios, PEG, P/B, and EV/EBITDA with real examples from TCS, HDFC Bank, Google, and NVIDIA. Includes Indian market sector benchmarks.

Investment EducationFebruary 8, 2026

HDFC Bank: Complete Business Analysis & Investment Guide

Deep dive into HDFC Bank's history, products, competitive moat, and current business - a beginner's guide to understanding Indian banking.

Stock Deep DiveFebruary 8, 2026

Understanding the NIFTY 50: India's Most Important Stock Market Index

Complete beginner's guide to the NIFTY 50 index: construction, top holdings, historical returns, vs SENSEX, and how to invest via index funds and ETFs.

Investment EducationFebruary 7, 2026

Portfolio Diversification: The Complete Beginner's Guide to Managing Risk

Build your first diversified portfolio step-by-step. Indian tax implications, asset classes, behavioral traps, real portfolio examples using TCS, HDFC, ITC, and more.

Investment EducationFebruary 5, 2026