B

Dollar Deposit Exchange Gain Tax Preview

3.60

Derivation Chain

Step 1 Record-high dollar deposits
→
Step 2 Confusion over taxation of exchange gains on personal foreign currency deposits
→
Step 3 Simulation of comprehensive income tax on exchange gains + interest income

Problem

A 50-something office worker opens a dollar deposit thinking 'I'll buy when the exchange rate is low,' but the tax treatment of exchange gains varies by product (deposit vs. fund vs. ETF), and it's unclear whether exchange gains count toward the 20 million KRW (approx. $15,000) threshold for comprehensive taxation of financial income. Misjudgment can lead to unexpected increases in health insurance premiums (500,000-1,000,000 KRW, approx. $375-$750 per year) or additional comprehensive income tax, and verifying this requires a tax accountant consultation (100,000-200,000 KRW, approx. $75-$150 per session).

Solution

Enter the dollar purchase date, amount, and planned sale date on the web to compare after-tax net proceeds across deposits, RPs, dollar ETFs, and dollar funds. It also factors in whether the comprehensive taxation threshold is exceeded and the impact on health insurance premiums, showing 'total tax + health insurance burden if you sell now' on one screen. A sell timing optimization simulation suggests strategies to minimize taxes.

Target: Office workers and self-employed individuals aged 45-58, holding dollar deposits of 10 million KRW (approx. $7,500) or more, middle-class individuals with financial income approaching 15 million KRW (approx. $11,250)
Revenue Model: Basic simulation free, annual tax optimization report PDF download at 5,000 KRW (approx. $3.75) per download, Premium (sell timing alerts + health insurance premium tracking) at 9,900 KRW (approx. $7.43) per month.
Ecosystem Role: Regulation
MVP Estimate: 2_weeks

NUMR-V Scores

N Novelty
3.0/5
U Urgency
4.0/5
M Market
4.0/5
R Realizability
4.0/5
V Validation
3.0/5
NUMR-V Scoring System
N Novelty1-5How uncommon the service is in market context.
U Urgency1-5How urgently users need this problem solved now.
M Market1-5Market size and growth potential from proxy indicators.
R Realizability1-5Buildability for a small team with realistic constraints.
V Validation1-5Validation signal quality from competition and demand data.
Each dimension is scored 1-5 and weighted into grade S/A/B/C/D.
N=.15 U=.20 M=.15 R=.30 V=.20

Feasibility (68%)

Tech Complexity
29.3/40
Data Availability
19.2/25
MVP Timeline
20.0/20
API Bonus
0.0/15
Feasibility Breakdown
Tech Complexity/ 40Difficulty of core implementation stack.
Data Availability/ 25Practical availability and cost of required data.
MVP Timeline/ 20Expected time to ship a usable MVP.
API Bonus/ 15Bonus for viable public API leverage.
Total 100 points; below 50% is filtered out.

Market Validation (57/100)

Competition
8.0/20
Market Demand
6.2/20
Timing
14.0/20
Revenue Signals
10.5/15
Pick-Axe Fit
10.5/15
Solo Buildability
8.0/10
Validation Breakdown
Competition/ 20Signal quality from competitor landscape.
Market Demand/ 20Demand proxies from search and mention patterns.
Timing/ 20Fit with current shifts in tech, behavior, and regulation.
Revenue Signals/ 15Reference evidence for monetization viability.
Pick-Axe Fit/ 15How well the concept serves participants in a trend.
Solo Buildability/ 10Practicality for lean-team implementation.
Total 100 points; below 50 is filtered out.

Technical Requirements

Frontend [medium] Backend [medium] Data Pipeline [low]
Dashboard