This paper proposes Kronos, a comprehensive and scalable pre-training framework specialized for candlestick chart (K-line) data in financial markets. Kronos introduces a specialized tokenizer that converts continuous market information into token sequences, preserving both price fluctuations and trading activity patterns. It is pre-trained with an autoregressive objective function using a large-scale multi-market corpus consisting of over 12 billion K-line records from 45 global exchanges. It demonstrates outstanding performance in zero-shot settings across a variety of financial tasks, outperforming existing methods in a variety of tasks, including price time series forecasting, volatility prediction, and synthetic K-line sequence generation. The pre-trained model is publicly available.