Polymarket's Bulgaria Election Call: 83.5¢ Conviction That Never Wavered

Bulgaria just held its eighth parliamentary election in five years. Ex-president Rumen Radev's Progressive Bulgaria party won 44.7% of the vote — an outright plurality that puts him in line for the prime ministership. The result matched what Polymarket traders had been pricing in since the market opened on March 15: an opening print of 83.5 cents, a brief dip to 77.2 cents on March 17, and then a relentless grind toward certainty that closed at 99.7 cents on election day.

The market was never below 77¢. For the 36 days it ran, the crowd never had real doubt.

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The Price Never Had a Second Opinion

Here's the full daily close series for the "Will Progressive Bulgaria win the most seats?" Yes token:

That March 17 dip — from 83.5¢ to 77.2¢ over two days — was the only real opportunity to get long at a discount. It lasted 72 hours. By March 20, a single-day +8.6% move recovered it all and then some. After that, the market consolidated between 87¢ and 89¢ for eleven straight days before the April 1 jump kicked off the final march to resolution.

Two things drove this structure. First, pre-election polling had PB around 35% vote share — a number that made most mainstream commentators cautious about calling a majority. Polymarket wasn't cautious. It looked at fragmented opposition (GERB–SDS at ~12%, PP–DB at ~13%, three or four smaller parties splitting the rest) and priced in the correct inference: 35% in that field wins most seats. Second, liquidity grew as the market aged. Daily volume went from $124K on March 15 to $57M on election day — a 460x expansion — which means the final prices reflect far more capital-at-risk than the early prints.

The pre-election polling vs. market-implied probability comparison is worth sitting with. Polls measured vote share. Markets measure win probability. A party polling 35% in a seven-way field needs no special information to win 40%+ of seats — it just needs the other six parties to keep fragmenting. Polymarket priced that inference correctly from day one. Most election commentary didn't.

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Volume Was the Real Signal

Volume alone told you the market had legs:

The acceleration from April 7 to April 17 is the interesting window. Price was already above 93¢ by April 7, so new capital entering wasn't moving the price much — it was confirming a settled view, not discovering one. That $15M → $52M volume expansion in ten days represents sophisticated capital arriving late, not early. The information was priced in weeks earlier.

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How to Pull This Yourself

The full analysis runs off the /v1/markets/{id}/prices and /v1/markets/{id}/metrics endpoints. Here's the exact code to reproduce the price trajectory and volume chart:

import os
import requests
import pandas as pd
import matplotlib.pyplot as plt
import matplotlib.dates as mdates

API_KEY = os.environ["POLYMARKETDATA_API_KEY"]
BASE = "https://api.polymarketdata.co/v1"
HEADERS = {"X-API-Key": API_KEY}

MARKET_SLUG = "will-progressive-bulgaria-pb-win-the-most-seats-in-the-2026-bulgarian-parliamentary-election"

def fetch_paginated(endpoint, params):
    results = []
    while True:
        r = requests.get(f"{BASE}/{endpoint}", headers=HEADERS, params=params, timeout=30)
        r.raise_for_status()
        data = r.json()
        results.extend(data["data"])
        cursor = data.get("metadata", {}).get("next_cursor")
        if not cursor:
            break
        params["cursor"] = cursor
    return results

# Fetch daily price and metrics
price_params = {
    "start_ts": "2026-03-15T00:00:00Z",
    "end_ts": "2026-04-20T00:00:00Z",
    "resolution": "1d",
}
metrics_params = {**price_params}

prices_raw = fetch_paginated(f"markets/{MARKET_SLUG}/prices", price_params)
metrics_raw = fetch_paginated(f"markets/{MARKET_SLUG}/metrics", metrics_params)

prices = pd.DataFrame(prices_raw)
prices["t"] = pd.to_datetime(prices["t"], utc=True)
prices = prices.rename(columns={"price": "yes_price"})

metrics = pd.DataFrame(metrics_raw)
metrics["t"] = pd.to_datetime(metrics["t"], utc=True)

df = prices.merge(metrics[["t", "volume"]], on="t", how="left")

# Plot: dual-axis price + volume
fig, ax1 = plt.subplots(figsize=(12, 5))

ax1.fill_between(df["t"], 0, df["volume"] / 1e6, alpha=0.2, color="#6366f1", label="Volume ($M)")
ax1.set_ylabel("Daily Volume ($M)", color="#6366f1")
ax1.tick_params(axis="y", labelcolor="#6366f1")
ax1.set_ylim(0, 80)

ax2 = ax1.twinx()
ax2.plot(df["t"], df["yes_price"], color="#10b981", linewidth=2.5, label="PB Yes Price")
ax2.axhline(0.835, color="#f59e0b", linestyle="--", linewidth=1.2, label="Opening price (83.5¢)")
ax2.set_ylabel("Implied Probability", color="#10b981")
ax2.tick_params(axis="y", labelcolor="#10b981")
ax2.set_ylim(0, 1.05)
ax2.yaxis.set_major_formatter(plt.FuncFormatter(lambda x, _: f"{x:.0%}"))

ax1.xaxis.set_major_formatter(mdates.DateFormatter("%b %d"))
ax1.xaxis.set_major_locator(mdates.WeekdayLocator(byweekday=0))
plt.setp(ax1.xaxis.get_majorticklabels(), rotation=30)

lines1, labels1 = ax1.get_legend_handles_labels()
lines2, labels2 = ax2.get_legend_handles_labels()
ax2.legend(lines1 + lines2, labels1 + labels2, loc="lower right")

ax1.set_title("Bulgaria Election 2026: PB Win Probability vs. Daily Volume", fontsize=13)
plt.tight_layout()
plt.savefig("bulgaria_election_2026.png", dpi=150)
plt.show()

If you want intraday data around the March 17 dip or the March 20 recovery, swap resolution to "1h" or "10m" and tighten the time window. The 1-minute data goes back 12+ months on pro+ plans.

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The Opponent's View

For context, here's what the "Will PP–DB (We Continue the Change) win most seats?" Yes token looked like over the same period:

• March 15: 2.1¢
• March 29: brief spike to 5¢ (a single day, immediately faded)
• April 19: 0.45¢

The market gave the incumbent pro-EU coalition essentially no shot from the start. PP–DB ended up at 13.2% of the vote — second place, but not close to first. The crowd read the coalition arithmetic correctly.

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What's the Next Trade

Bulgaria has a presidential election coming in Fall 2026. The "Next Prime Minister of Bulgaria" market already has Radev at 95.5 cents — near-certainty he takes the PM role, given PB's parliamentary majority. That market has ~$260K in volume and is likely to stay near 1.0 unless there's a coalition surprise.

The more interesting open question is the presidential race. Incumbent Iliana Iotova (who became president when Radev resigned in January) leads at ~41.5¢, with Nikolai Denkov from the pro-EU PP–DB bloc at ~26.5¢. If Radev consolidates power as PM and builds a stable government — the first one Bulgaria has had since 2021 — Iotova's incumbency advantage could widen. That race is five months out and currently undertraded relative to what we know about Bulgarian politics post-election.

The Bulgarian election markets just demonstrated something useful: niche European elections aren't exempt from crowd intelligence. If you were long PB Yes at any price below 90¢, you got paid. The crowd was right, and it was right early.

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All data from the polymarketdata.co API. Full endpoint reference at polymarketdata.co/docs.