To augment the relative prices of carbon content emeries to green energies, many governments have imposed carbon prices and proved subsidies to green energy production. Given the imperative role of green finance for global energy transitions, we investigate whether oil equity transmits any significant signal to green investments and vice-versa as substitute commodities. To this end, we apply three novel time-series methods; namely, the Cross-Quantilogram, Time-frequency connectedness and Cross-spectral quantile coherency approaches to analyze daily return series of green bonds, green equity, and selected oil companies' equity returns as dirty investments ranging 30th August 2014 till 9th November 2021. Our empirical investigation demonstrates that dirty investments (oil equity) transmit negative volatility spillovers to green investments (both bond and equity). On the contrary, dirty investment returns respond positively to both green bonds and green equity returns. The co-movement between green and dirty markets is more pronounced in the short time. We also confirm that oil equities induce higher volatility on green markets than vice versa, with green bonds being more vulnerable to this impact. The paper provides policy implications for investors' decision-making making process on risk hedging.

为了提高碳含量的能源相对于绿色能源的相对价格，许多政府实施了碳价格并对绿色能源生产提供补贴。鉴于绿色金融对全球能源转型的必要作用，我们调查石油股权是否向绿色投资传递任何重要信号，反之亦然作为替代商品。为此，我们应用了三种新颖的时间序列方法；即，使用交叉数量图、时频连通性和交叉光谱分位数相干性方法来分析 2014 年 8 月 30 日至 2021 年 11 月 9 日期间作为肮脏投资的绿色债券、绿色股票和选定石油公司的股票回报的每日回报序列。我们的实证调查表明，肮脏投资（石油股票）将负波动溢出效应传递给绿色投资（债券和股票）。相反，肮脏投资回报对绿色债券和绿色股票回报均有积极反应。绿色市场和肮脏市场之间的联动在短期内更加明显。我们还证实，与绿色市场相比，石油股票在绿色市场上引发的波动性更高，而绿色债券更容易受到这种影响。本文为投资者的风险对冲决策过程提供了政策启示。我们还证实，与绿色市场相比，石油股票在绿色市场上引发的波动性更高，而绿色债券更容易受到这种影响。本文为投资者的风险对冲决策过程提供了政策启示。我们还证实，与绿色市场相比，石油股票在绿色市场上引发的波动性更高，而绿色债券更容易受到这种影响。本文为投资者的风险对冲决策过程提供了政策启示。