fn initialize(env: soroban_sdk::Env, admin: soroban_sdk::Address)
fn add_transaction(
env: soroban_sdk::Env,
cusip: soroban_sdk::String,
price: i128,
amount: i128,
trade_type: soroban_sdk::String,
)
fn get_transactions(
env: soroban_sdk::Env,
cusip: soroban_sdk::String,
) -> soroban_sdk::Vec
fn get_all_latest_prices(
env: soroban_sdk::Env,
limit: Option,
) -> soroban_sdk::Vec