# THE LILY PAD EXCHANGE

WEEKLY QUACK CHALLENGE! · challenge 9 · medium · 5 guesses

> Feathers are flying at the Lily Pad Exchange. Director Goldeneye slaps a stack of ticker tape on Duckbert's desk. "Markets closed three minutes ago and every broker in the building is screaming about who had the big day. It's not who moved the most per share — any fancy-feathered fool can clock a big price swing on a thin float. I want to know which sector actually moved the most money. Total market-cap change. Close minus open, times every share outstanding. Sum it by sector. Bring me the winner before I have to answer to the board, Duckbert."

## Task

Each ticker’s daily price move is its last trade price minus its first; multiply that by its shares outstanding (from `read_parquet(data/files/202635_09_lily_pad/shares_outstanding.parquet)`) to get its market-cap change. Return the sector with the largest total market-cap change; on a tie, the alphabetically first. You will be working with the `trades` and `companies` tables and the shares file.

## Tables

### `trades` (21 rows)

| column | type |
| --- | --- |
| ticker | VARCHAR |
| ts | TIMESTAMP |
| price | DECIMAL(10,2) |

### `companies` (7 rows)

| column | type |
| --- | --- |
| ticker | VARCHAR |
| name | VARCHAR |
| sector | VARCHAR |

## Files

### `data/files/202635_09_lily_pad/shares_outstanding.parquet` (7 rows)

Download: https://dbquacks.com/data/files/202635_09_lily_pad/shares_outstanding.parquet

| column | type |
| --- | --- |
| ticker | VARCHAR |
| shares | INTEGER |

## Data

The tables live in a DuckDB database: https://dbquacks.com/data/databases/weekly_202635_09_lily_pad.duckdb

To query it outside the browser, attach it read-only:

```sql
ATTACH 'https://dbquacks.com/data/databases/weekly_202635_09_lily_pad.duckdb' AS db (READ_ONLY);
USE db;
```

Play it in the browser: https://dbquacks.com/challenges/weekly/9

## Answer

The expected answer is not published. Submit on the page to have it checked.