Article
Fundraising

The Startup Investment Terms Glossary

2026.05.30·13 min·OPENSEED

Write an IR deck or a business plan and you'll run into a flood of investment terms you use without quite knowing what they mean. Pre/post-money, TAM/SAM/SOM, FPF, convertible preferred stock, MFN, funding rounds — names you've heard, but ask for 'the precise definition and how to calculate it' and most people get stuck. This article is a glossary of the investment terms founders search for most, organized as definition → how to read it → calculation and example. Read each entry on its own, or look one up quickly right before an IR meeting or a review.

Intro.

#Pre-Money / Post-Money Valuation — Company Value Before and After Investment

This is where every valuation negotiation starts. Pre-money is your company's value 'right before' receiving investment; post-money is your company's value 'right after' the investment lands. The relationship between the two is simple: post-money = pre-money + investment amount.

TermHow to Read ItDefinition
pre-moneypre-moneyCompany value right before investment (excludes the investment amount)
post-moneypost-moneyCompany value right after investment (includes the investment amount)
Ownership percentageInvestment amount ÷ post-moneyThe percentage of new shares the investor receives

Example — if a company with a ₩2B pre-money valuation raises ₩500M, the post-money valuation is ₩2.5B. The investor's ownership stake is ₩500M ÷ ₩2.5B = 20%. A common mistake founders make is calculating it as '₩500M into a ₩2B company = 5/20 = 25%.' The denominator for ownership percentage is always post-money.

주의
If a negotiation just states 'valuation: ₩2B,' always confirm whether that's pre- or post-money. Even with an identical number, a ₩2B pre-money valuation and a ₩2B post-money valuation produce very different founder ownership.
02

#TAM/SAM/SOM — How to Read the 3 Tiers of Market Size

This is a 3-tier framework for narrowing market size from largest to smallest. Read them as 'tam,' 'sam,' and 'som.' As you move from top to bottom, the market narrows to something increasingly realistic — 'what I can actually capture.'

TermHow to Read ItMeaning
TAMTotal Addressable MarketThe entire market — if you captured all of it, with no constraints
SAMServiceable Available MarketThe market your product and geography can actually reach
SOMServiceable Obtainable MarketThe realistic share you're targeting to capture in your first few years

Example — for a domestic tax-filing SaaS product built for small business owners, TAM would be 'the global accounting-software market for SMBs,' SAM would be 'the domestic tax software market for small business owners,' and SOM would be 'the share we can realistically capture domestically within 3 years.' What reviewers and VCs care about most isn't TAM — it's the basis behind your SOM.

TIP
Cite a huge TAM with no SOM justification, and you'll get docked for 'TAM inflation.' SOM needs to be calculated bottom-up (see #6 below) to earn credibility.
03

#FPF (Founder-Problem Fit) — How Well the Founder Fits the Problem

FPF stands for 'Founder-Problem Fit' — essentially, 'why are you the right person to solve this problem.' It's a concept that precedes PMF (Product-Market Fit): before asking whether the product fits the market, it asks whether the founder fits the problem. It's the central lens investors use to judge a team at the pre-seed and early stages.

  • Why this problem — has the founder personally experienced it, or do they deeply understand it?
  • Why now — what shift in market or technology makes this solvable now?
  • Why you — what unique experience, network, or expertise makes you the one to solve it?
TIP
Strong FPF gets you funded even when the product is still rough. Weak FPF makes you look like 'anyone could build this,' which makes early investment hard to secure. The problem-definition section of a business plan is, in effect, where you prove FPF.
04

#Convertible Preferred Stock (RCPS) and the MFN Clause

The standard investment instrument in Korean startup deals is convertible preferred stock — more precisely, RCPS (Redeemable Convertible Preferred Stock). It's preferred stock that carries both a right to convert into common stock (conversion right) and a right to demand repayment of principal (redemption right). The structure lets investors hedge their downside through redemption while capturing upside through conversion.

TermHow to Read ItCore Idea
RCPSRedeemable Convertible Preferred StockPreferred stock with both redemption and conversion rights (Korea's standard)
Conversion rightThe right to convert into common stock (upside)
Redemption rightThe right to get principal plus interest back (downside protection)
MFNMost Favored Nation clauseIf a later investor gets better terms, existing investors automatically get those terms too

An MFN (Most Favored Nation) clause is a promise that 'if any other investor in this round or a future round gets more favorable terms, those same terms automatically extend to existing investors.' It shows up especially often in SAFEs and convertible notes. For founders, a concession made to one investor can spread across the entire round, so you need to check exactly what the clause covers — price, liquidation preference, consent rights, and so on.

주의
Clauses like MFN, liquidation preference, and consent rights can each single-handedly reshape the economics of an entire round. Review them clause by clause before signing a term sheet. (Contract enforceability should always be reviewed by a qualified professional.)
05

#Funding Round Classifications — Seed, Pre-A, Series A and Beyond

Rounds are categorized by a company's maturity and what the capital is meant to prove. Since absolute dollar amounts shift with market conditions, it's more accurate to think in terms of 'what stage has this company proven,' not the amount raised.

RoundWhat You Need to ProveTypical Purpose
Pre-SeedFPF — fit between founder and problemMVP and early validation
SeedEarly signs of PMF, real usersFinishing the product, entering the market
Pre-AEarly growth-stage tractionA bridge to Series A
Series AA repeatable growth formula (PMF)Scaling and expanding the org
Series B+Unit economics, market shareFull-scale expansion, going international
TIP
Rounds are defined not by 'how much you raised' but by 'what you proved.' The same ₩500M could be a Series A if PMF is proven, or still a seed round if it's not yet validated.
06

#Bottom-Up vs. Top-Down Revenue Estimates

These are the two directions for calculating revenue or market size. Top-down works down from 'what % of a big market,' while bottom-up builds up from 'customer count × price × frequency.' Reviewers and VCs trust bottom-up.

ApproachCalculation DirectionExample
Top-DownTotal market × market share %1% of a ₩10T market = ₩100B (weak justification)
Bottom-UpCustomer count × price × purchase frequency10,000 customers × ₩30,000/month × 12 months = ₩3.6B (strong justification)

Top-down conveys a sense that 'the market is big,' but it can't explain why you'd capture that specific percentage. Bottom-up is built from verifiable variables — customer acquisition path, price, conversion rate — so it holds up under questioning. Always calculate SOM bottom-up.

07

#Quick Reference for Commonly Confused Basic Terms

TermHow to Read ItOne-Line Definition
co-founderco-founderA person who founded the company together, splitting equity and roles
cap tablecap tableA table showing every shareholder's ownership
dilutiondilutionThe reduction in existing shareholders' ownership when new shares are issued
runwayrunwayThe number of months your current cash can sustain the company
burn rateburn rateMonthly net cash outflow
dry powderdry powderCapital a VC has raised but not yet deployed
lead investorlead investorThe investor who leads the round and sets its terms
TIP
Using terms precisely is itself a signal of credibility. Mix up pre- and post-money, or confuse TAM with SOM, in an IR meeting, and you read as 'an unprepared team' regardless of your actual content.
Summary.

#Once You Know the Terms, the Next Question Is 'Do My Numbers Hold Up?'

Knowing investment terminology accurately is just the starting point. The real evaluation comes down to: 'Is your valuation justified? Does your SOM hold up as a bottom-up calculation? Is FPF actually proven in your problem definition?' Use the right terms with weak number logic, and you'll get stuck in the same place.

CTA
OpenSeed has 15 AI reviewers cross-check the number logic in your business plan and IR from a market, finance, and team perspective. It catches, before you submit, the weaknesses reviewers look for — TAM inflation, revenue estimates built only top-down, and valuations with no justification.
광고

You've Got the Terms Right — Now Check Your Numbers

15 AI reviewers cross-check whether your valuation, SOM, and revenue estimates hold up from a reviewer's point of view.

🔒 Free during beta · your submission isn't saved

Start Free AI Feedback →

관련 AI 피드백 서비스.

AI 피드백
사업계획서 AI 추천
AI 피드백
사업계획서 피드백
AI 피드백
사업계획서 검토
RELATED · Same categoryFundraising
Why Seed-Stage VCs Weigh 'Team Risk' So Heavily — Persuasion Strategies for Solo Founders, Non-Technical CEOs, and Teams With No Domain Experience2026.07.10 · 8 minDue Diligence and Data Room Prep — What VCs Demand After the Term Sheet2026.06.30 · 9 minHow to Use Follow-Up Emails After an Investor Pass to Stay in the Relationship and Land the Next Round2026.06.30 · 8 minThey Were Speaking Different Languages — Why Great Technology Fails When It Doesn't Translate2026.06.29 · 8 minThe Shareholder Consent and Board Resolution Documents Founders Must Prepare Before Series A2026.06.28 · 8 min
← Back to Discovery